Copyright: Copyright © 1992-1999 Digital Light & Color, All Rights Reserved


Contents
Picture Window 2.5

Getting Started

Glossary

Image Basics

Using Transformations

Masks

Main Window

Tool Bar

Main Menu

File

Edit

Window

Transformation

Mask

Tools

Tips

Troubleshooting

Working with 16-bit black and white and 48-bit color images

Digital Light & Color

Contact Information

Mail:

Digital Light & Color

P.O. Box 382908

Cambridge MA 02238

Orders:

(800) 243-1515 ext. 800  Voice

(215) 997-2571  FAX

Information:

(617) 489-8858  Voice

info@dl-c.com

Support:

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(617) 576-1062  FAX

support@dl-c.com

World Wide Web:

http://www.dl-c.com

Copyright © 1992-1999, Digital Light & Color
All Rights Reserved


Glossary

Amount

Auto Preview

AVI File

Binary Images

Black and White Images

BMP File

CMYK

Color Images

Color Spaces

Display Adapter

Dynamic Range

EPS File

FlashPix File

Gamma

GIF File

Halftone

Histogram

HSL

HSV

Hue

JPEG File

Luminance

Mask

Monitor

PCX File

PNG File

Perspective Correction

PhotoCD

Pixel

Posterize

Preview

Primary Color

Resolution

RGB

Saturation

Scanner

Solarize

Targa

Thumbnail

TIFF File

Transformation

TWAIN

White Point

Zoom Factor


Tips

Cloning

Color balancing

Colorizing black and white images

Extending the dynamic range of slide film

Fog filter

How to use your photographs in documents and presentations

Lightening or darkening an image

Masking

Matching monitor and print

Memory

PhotoCD Scanning

Printing Tips

Rainbow gradients

Rotating an image

Scanning Tips

Sepia toned prints

Vignetting


Image Basics

Pixels

The term pixel is derived from "Picture Element". A pixel is a tiny dot of a particular color; images are made up of many of these dots arranged in rows and columns. Whether being displayed on your computer screen or printed on film or paper, digital images are made up the same rows and columns of pixels. By zooming an image in to a high magnification factor, you can see its individual pixels.

How transparencies or prints are digitized

When a photograph is digitized, a scanner measures the color of the image at each pixel location and stores this information as three numbers representing the amounts of each of the three additive primary colors: red, green, and blue. Each color component is stored as 8 bits of data which gives a range of values from 0 to 255. A color pixel therefore consists of 24 bits of data; this means that each pixel can represent any of about 16 million colors.

How digital images are displayed or printed

To view a digital image, whether on a computer screen, as a transparency, or as a print, its digital data must be converted back to a physical color image. In the case of a display screen this is done by illuminating tiny clusters of red, green, and blue dots on the face of the picture tube, one for each pixel, in proportion to that pixel's red, green, and blue values. To create a transparency, a film recorder photographs an internal screen which exposes the film a line at a time. Digital printers use a wide variety of technologies from evaporating tiny dots of colored dyes onto special paper to exposing photographic paper directly from a laser or internal screen to create color images.

Resolution

The quality of a digital image is greatly affected by its resolution. The resolution of an image is the number of pixels per inch. Like film grain, the smaller the pixels, the sharper the image can be. High quality images are thus made up of a very large number of pixels.

Color Images

Color images are made up of color pixels, each of which is represented internally in the computer as three bytes (24 bits) defining its red, green, and blue values. This means that a color image 1000 pixels wide and 1000 pixels high occupies 3MB of memory.

Black and White Images

Black and white images are made up of gray pixels each of which is represented internally as a single byte (8 bits) whose value describes its brightness. Thus a black and white image uses three times less memory than a color image of the same dimensions. You can use black and white images to represent black and white photographs or as masks for other images.

Binary Images

Binary images are made up of pixels that are either black or white; each binary pixel is represented as a single bit. Binary images use eight times less memory than black and white images. While Picture Window supports importing and using binary images, they are not very useful for representing photographic images.

Note: 16-bit black and white images and 48-bit color images as described below are supported only by the Pro version of Picture Window.

16-bit Black and White Images

Black and white images are made up of gray pixels each of which is represented internally as a single byte (8 bits) whose value describes its brightness. Thus a black and white image uses three times less memory than a color image of the same dimensions.

This type of image is capable of handling a much larger dynamic range than a normal (8-bit) black and white image since each pixel value has a range of 0..65535 instead of just 0..255. Although this extended range supports a subtlety of variation much greater than the human eye can distinguish, it allows transformations such as curve adjustments to be applied to an image while preserving its smooth tonal range. This is particularly useful when scanning images using a scanner capable of capturing and transferring more than 8 bits of image data per component.

48-bit Color Images

48-bit color images are made up of color pixels, each of which is represented internally in the computer as six bytes (48 bits) defining its red, green, and blue values, each of which is stored as a 16-bit quantity. This means that a color image 1000 pixels wide and 1000 pixels high occupies 6MB of memory.

This type of image is capable of handling a much larger dynamic range than a normal (24-bit) color image since each component has a range of 0..65535 instead of just 0..255. Although this extended range supports a subtlety of variation much greater than the human eye can distinguish, it allows transformations such as curve adjustments to be applied to an image while preserving its smooth tonal range. This is particularly useful when scanning images using a scanner capable of capturing and transferring more than 8 bits of image data per component.


Toolbar

The Picture Window toolbar is a strip of icons displayed just below the main menu or down the left edge of the workspace. Clicking on an icon with the left mouse button is just like selecting an action from the menu. Leaving the cursor over one of the toolbar icons pops up a short description of the action associated with the icon. The icons on the toolbar are:

File Open PhotoCD

File Open

File Browse

File Save As

File Acquire

Zoom In

Zoom In and Resize

Zoom Out

Zoom to 1:1

Shrink to Fit Window

Next Window

Mask

Zoom Tool

Magnifier Tool

Readout Tool

Clone Tool

Paint Tool

Line and Arrow Tool

Miscellaneous Tools

Context-Sensitive Help

You can select the orientation of the toolbar or turn it off from the Window Menu.


Main Window

Picture Window's main window consists of several components:

The main menu,

The toolbar, and

The workspace


Workspace

The workspace is the large area of the main window starting just below (or to the right of) the toolbar.

You can change the color of the workspace background with the File Preferences command. A dark, neutral gray is recommended for the background color.

Image Windows and Dialog Windows

The workspace is like the surface of a giant light table on which you can place any number of images, each in its own window. These image windows can each be positioned, resized, zoomed, and scrolled independently. Running transformations or a tools may create additional windows called dialog boxes which you use to tell Picture Window what you want it to do.

Each image window is a view of all or part of an underlying image file. Enlarging or reducing the magnification of the windows by zooming in or out does not affect the image data, only your view of it. Similarly, whether you view color images using a display card set to 16 million color mode or only 256 colors, the image data is always stored using 24 bits per pixel or 16 million colors (or 8 bits per pixel for black and white images).

Image Borders

Image windows contain an image surrounded by a border. You can change the color and width of the image border with the File Preferences command. It is recommended that you keep a relatively narrow white border around your images to provide a reference white against which you can judge the brightness of your image.

Workspace Scroll Bars

As soon as any window is moved off of the visible area of the workspace, scroll bars automatically appear at the right and/or bottom edges of the workspace so you can scroll different parts of the workspace into view.

Window Title Bars

Each window has a title bar along its top which contains a caption. For dialog windows, the window caption is the name of the command that created the dialog. For image windows, the caption starts with the file name of the image in the window, if any. If the window contains data that has never been saved in or loaded from a file, it is given the name "Untitled" followed by a number. These numbers are assigned in increasing order; the larger the number, the more recently the window was created. Following the file name in the caption is the zoom factor of the form n:1 for magnified views and 1:n for reduced views. The zoom factor is the ratio of screen pixels to image pixels.

Moving Windows

You can move windows around on the workspace by clicking and dragging the by their caption bar.

Selecting Windows

Clicking anywhere on a window causes it to become the current window and to be displayed on top of any other windows it may overlap. To bring a window to the top when it is totally obscured by other windows, either select the name of the window from the list displayed at the end of the Window menu or execute the Window Next command (also available as [image] on the toolbar) until the desired window appears on top.

Resizing Windows

If a window has a wide border, you can resize it by clicking and dragging any of its corners or sides.

Maximizing Windows

You can maximize an image window by clicking on the maximize icon in the upper right corner of the window. You can also maximize a window by double-clicking on its title bar. This causes the window to temporarily occupy the entire workspace. To restore the window to its original size, click the upper right corner again.

Minimizing Windows

You can minimize an image window by clicking on the minimize icon which is just to the left of the maximize icon. This shrinks the window to an small title bar displayed near the bottom of the workspace. Minimizing a window frees up some of the memory required to store its information and reduces screen clutter. To restore the window to its original size, double-click its title bar.

Closing Windows

To close a window, click the close icon in its upper right corner, double-click the icon in the upper left corner of the window, or use the File Close command.


File Menu

New

Open

Open PhotoCD

Browse

Save

Save As

Close

Revert

Acquire

Select Source

Print

Print Setup

File Slide Show

Preferences

Associations

Calibrate

Exit


Edit Menu

Undo

Undo All

Copy

Paste


Window Menu

Info

Count Colors

Grid

Blink

No Tool Bar

Tool Bar at Top

Tool Bar at Left

Expand

Fit

Zoom In and Resize

Zoom In

Zoom Out

Zoom Factor

Zoom to 1:1

Next

Arrange Icons

Cascade

Close All


Transformation Menu

Geometry

Copy

Mirror/Rotate

Add Border

Crop

Resize

Warp

Displace

Gray

Negative

Levels and Color

Brightness Curve

Brightness

Tint

Light Falloff

Gamma Adjust

Combine Channels

Color

Balance

Curves

Saturation

Extract Channel

Monochrome

Correction

Registration

Convert

Filter

Composite

Gradient

Blur

Sharpen

Text

Special Effects

Emboss

Edge

Difference

Add Noise

High Contrast

Tile

Kaleidoscope

Spiral

Equalize

Stereo

Calendar

Halftone

Interlace

Posterize

Grid

Texture

Layout


Mask Menu

The mask menu consists of the single item New possibly followed by a list of mask image names. The list includes all black and white images whose width and height in pixels are the same as the current image.

Selecting New initiates the process of creating a new mask for the current image. It brings up the Mask Dialog and clears the entire mask overlay. When you click OK on the Mask Dialog, the mask overlay is peeled off the input image and placed in a new image window. Clicking Cancel on the Mask Dialog aborts the entire mask operation.

Selecting one of the named masks from the Mask menu brings up the Mask Dialog with the mask image as the initial mask overlay over the current image. This lets you alter the mask using the controls in the Mask Dialog. When you click OK on the Mask Dialog, the overlay is peeled off the input image and replaces the original mask image. Clicking Cancel on the Mask Dialog restores the original mask image.

Mask Dialog

Masks

Using Masks with Transformations

Using Masks with Tools


Tools Menu

Readout

Zoom

Magnifier

Clone

Paint

Line and Arrow

Miscellaneous


File Open

This command is used to load an image file into a new window. To access PhotoCD images, use File Open PhotoCD.

The File Open command displays a standard Windows dialog box which lets you select the file you wish to open and the type of the file. Picture Window supports a number of standard image file formats

First select the type of the file you wish to open and then select the file name. When you click Open, Picture Window reads the file into memory and creates a new window containing the image.

Picture Window uses Explorer-style File Open dialog boxes -- this means that:

1) You can use long filenames.

2) You can delete or rename files. To delete a file, click on its name to select it and then press the Del key. To rename a file, select it and then after a short pause click on it again -- at this point you can type over the name with a new name.

3) You can create, delete, or rename folders. To create a new folder, click on the [image] icon in the toolbar at the top of the dialog box. Folders are deleted or renamed the same way as files (see above).

4) You can select multiple files. To select additional individual files, Control-click (hold down the Ctrl key while you click) on the filenames. To select a range of files, click on the first one and the Shift-click (hold down the Shift key while you click) on the last one. If you select multiple files, each one is opened into its own window when you click Open.

5) As a shortcut for opening a file, double-click on its filename.

6) To go up to the parent folder, click the [image] icon in the toolbar at the top of the dialog box.

7) To open a subfolder, double click on it.

Notes:

To avoid confusion, Picture Window requires that the file extension match the file type. TIFF files may have an extension of either TIFF or TIF; JPEG files may have an extension of either JPEG or JPG.

If you use File Open to access a PhotoCD (.PCD) file, Picture Window will display a secondary dialog box requesting the image size you want to load (512x768, 1024x1536, or 2048x3072).

If a selected file is already open then you will be asked whether you wish to re-open it or just bring the corresponding window to the top. To make a copy of a file in another (untitled) window, use the Copy transformation. The same file cannot be open in two different windows.


File New

This command is used to create an image window filled with a solid color or gray level. Once you specify the size of the image and its color, Picture Window creates a new image of that size and color.

The File New dialog contains the following controls:

Width, Height, and Resolution

These controls are used to set the resolution and size of the new image.

Background Color

This Color Control is used to set the color of the new image. To set the image color click the large button.

Type

This Popup List Control sets the type of the new image to Binary, Black and White, Color, 16-bit Black and White, or 48-bit Color. (Note: 16-bit black and white and 48-bit color are supported only in the Pro version of Picture Window)


File Save

File Save

The File Save command saves the current image as a disk file. If the current image is untitled, this command acts like File Save As (see below). Otherwise, the current image is saved with the same name and file type as when it was last opened or saved.

File Save As

The File Save As command saves the current image as a disk file. Unlike File Save, it always lets you specify a new file name. First select the file type you want to use and then the image file name, then click OK.

If a file of the selected name is already open, you will get an error message. You must close this open window before saving; otherwise there would be two windows with the same name containing different images.

Picture Window uses Explorer-style File Save As dialog boxes -- this means that:

1) You can use long filenames.

2) You can delete or rename files. To delete a file, click on its name to select it and then press the Del key. To rename a file, select it and then after a short pause click on it again -- at this point you can type over the name with a new name.

3) You can create, delete, or rename folders. To create a new folder, click on the [image] icon in the toolbar at the top of the dialog box. Folders are deleted or renamed the same way as files (see above).

4) As a shortcut for replacing a file, double-click on its filename.

5) To go up to the parent folder, click the [image] icon in the toolbar at the top of the dialog box.

6) To open a subfolder, double click on it.

To avoid confusion, Picture Window requires that the file extension match the file type. TIFF files may have an extension of either TIFF or TIF; JPEG files may have an extension of either JPEG or JPG.

Saving Files in JPEG format

When you choose JPEG as the file type Picture Window displays a dialog box requesting image quality information. These settings are preserved across Picture Window sessions.

Quality

The quality slider lets you select a quality level from 0 to 100%. Higher quality levels are more faithful to the original image; lower quality levels yield better compression ratios.

Use a setting of 97% to achieve good compression (typically 4X to 10X) with little or no visible reduction in image quality. A setting of 90% or lower will compress the image significantly more but image quality will start to degrade. Settings lower than 90% will give rise to more visible artifacts.

To get a feel for the effects of different JPEG settings, save the same test image in an uncompressed format such as BMP and in JPEG format. Then open both files in side-by-side windows and zoom in to compare the images in detail. JPEG artifacts are usually most noticable along sharp boundaries between areas of contrasting solid colors.

Color Sampling

This control lets you select, if you are saving a color image, how much the color information is compressed. Since JPEG compression works by first separating the luminance (brightness) information from the chrominance (color information), each component can be compressed differently. For best quality, select 4:4:4; to achieve higher compression, select 4:2:2 or 4:1:1.

Saving Files in FlashPix format

When you choose FlashPix as the file type Picture Window displays a dialog box requesting image compression and quality information. These settings are preserved across Picture Window sessions.

Compression

This control lets you select whether you want to save an uncompressed or a JPEG-compressed file. If you select no compression then all the information in the image will be preserved; if you select JPEG, then there will be a loss of quality that runs from nearly undetectable at quality settings (see below) of 95 or above to very noticable at lower settings. The higher the quality you select, however, the larger the resultant file size.

Quality

The quality slider lets you select a quality level from 0 to 100%. Higher quality levels are more faithful to the original image; lower quality levels yield better compression ratios.

Use a setting of 97% to achieve good compression (typically 4X to 10X) with little or no visible reduction in image quality. A setting of 90% or lower will compress the image significantly more but image quality will start to degrade. Settings lower than 90% will give rise to more visible artifacts.

To get a feel for the effects of different JPEG settings, save the same test image in an uncompressed format such as BMP and in JPEG format. Then open both files in side-by-side windows and zoom in to compare the images in detail. JPEG artifacts are usually most noticable along sharp boundaries between areas of contrasting solid colors.

Saving 16-bit Black and White or 48-bit Color Images (Pro version only)

These types of files can only be saved as TIFF files as the other formats do not support more than 8 bits per component.


File Open PhotoCD

This command reads an image from a PhotoCD into a new image window.

Before executing this command, make sure you have loaded a PhotoCD in your CD-ROM drive. Do not remove the PhotoCD or change disks while the PhotoCD dialog is active. Only PhotoCD-compatible CD-ROM drives can read PhotoCDs.

The PhotoCD Dialog contains the following elements:

Image Number

If you know the number of the image you want to load, enter it directly into the image number control or browse the images on the disk one at a time using the arrow buttons.

Contact Sheet

Click this button to pop up a contact sheet of all the images on your PhotoCD. To select an image from the contact sheet, just click on it to return to the PhotoCD dialog with that image selected.

Thumbnail Image and Crop Box

This window displays a low resolution version of the currently selected PhotoCD image. Superimposed over the image is a crop box which you can reposition by dragging its corners, sides, or interior. This box provides rough cropping only; the Crop Transformation lets you to crop more precisely.

If your PhotoCD was made from mounted slides, this is a good time to trim off any black border created by the inside edges of the slide mount.

Resolution

This Popup List Control lets you select which of the five different versions of the currently selected image you want to read in. The higher the resolution, the higher the image quality but the more memory the image will take up. As a rule of thumb, the 512x768 image is good enough to make 4x5 prints and the 1024x1536 image is good enough to make 8x10s.

Orientation

This Popup List Control lets you select one of four 90 degree rotations of the input image. You only need to do this if the PhotoCD operator scanned your film incorrectly. You can also fix orientation problems later with the Mirror/Rotate Transformation.

When open PhotoCD images in low memory situations, it may take a very long time to read an image that is oriented in portrait mode. In this case, reading it in landscape mode and using the Mirror/Rotate Transformation is much faster.

Image Size

This control provides a readout of the width and height of the portion of the currently selected image selected by the crop box.

File Size

This control provides a readout of the image size in bytes of the portion of the currently selected image inside the crop box.

Serial Number

This control provides a readout of the serial number imprinted on the PhotoCD (right near the edge of the hole in the middle of the disk). The last four digits of the serial number are also printed in the lower left corner of the index print that is place in the jewel case in which the CD is returned.

Brightness

Adjusting the brightness slider controls the brightness of midtones in the image, leaving the highlights and shadows unchanged. You can control brightness more precisely later using the Brightness, Brightness Curve, or Levels and Color Transformations.

Dynamic Range

This control has two sliders. Picture Window scans the image for the brightest and darkest pixels in the central 90% of the frame (a 5% margin is ignored to avoid measuring the edge of the slide mount, if any). The brightness levels of these points are displayed as two vertical marks just below the dynamic range gray scale. The white slider adjusts the brightness of the image highlights; the black slider adjusts darkness of the image shadows. Moving the sliders closer together reduces overall contrast; moving them apart increases contrast. Moving the sliders to the ends of the gray scale makes the darkest pixels black and the lightest pixels white. You can control dynamic range more precisely later using the Brightness Curve or the Levels and Color Transformations.

Saturation

Adjusting this slider varies the overall image saturation. Setting saturation to zero makes the image black and white; a middle value leaves the saturation unchanged; larger values enhance the saturation. You can control saturation more precisely later using the Saturation or Color Curves Transformations.


Contact Sheet

The contact sheet displays thumbnail representations of all of the images on a PhotoCD in rows and columns. Each image is labeled with its image number, just like the index print that comes with the PhotoCD. Clicking on an image returns you to the main PhotoCD dialog with that image selected.

To print a summary of all the images on the PhotoCD, first wait for all the images to be read in and then click the Print button. This displays a standard Windows Print dialog box which lets you select a printer and print options. When you click OK the contact sheet is printed on the selected printer.

To return to the PhotoCD dialog box without selecting an image, click the Cancel button or close the Contact Sheet dialog box.


File Browse

The File Browse command lets you view miniature versions of all the image files in a given folder, providing a quick and convenient way to locate, review, and access your image files. You can even print the miniatures to create convenient reference sheets.

Select a folder
Select File Browse from the main menu. Picture Window then displays a File Browse dialog box similar to the standard Windows File Save dialog box. Use this to open the folder whose contents you wish to view and then click the Select button. When browsing folders on CD-ROM, make sure no files are highlighted when you click Select.

View the images
Once you have selected a folder, Picture Window displays a large, resizable dialog box and starts reading all the image files in the folder and displaying miniatures of each image in rows and columns. The pathname of the folder you selected is displayed in the title bar of the dialog box. If necessary, a vertical scroll bar appears at the right to let you scroll the display up and down. Displayed above each image are its filename, size in bytes, and the date it was last modified.

Select the Images you want to open
Select one or more files by clicking on them. Selected files are highlighted by an indented border and a change in the background color from white to black. To deselect a file just click on it a second time.

You can select all of the files in the folder by clicking on the Select All button or deselect all of the files with the Select None button. You don't have to wait for all the images to be displayed before starting to select files. To switch to a new folder, click the Select Folder... button.

Open the images
Once you have selected the files you want to open, click the Open button and they will all be opened, each in its own window. Or, you can simply double-click on the last file to open it and any other selected files.

At this point the File Browse dialog box remains open with no files selected so you can, for example, switch folders and open additional files. To close the File Browse dialog box without opening any additional files, click the Cancel button or close the File Browse window. Again, you don't have to wait for all the images to be read in before clicking Open or Cancel although there may be a short delay due to file reading before your actions take effect.

Printing a reference sheet
To print miniatures of all the images in the folder, click the Print button. This will display a standard Windows Print Setup dialog box you can use to select and configure your printer. When you click OK, a Print Options dialog box is displayed. The Print Options dialog box lets you select various print options:

Print at
If you select Screen Resolution, printing will be very fast but printed images may lack detail.

If you select Printer Resolution, printed images will contain more detail (especially large images printed at large sizes), but each image will have to be re-read from the disk during the printing process.

Image size
This control lets you specify what size you want each image to be on the printed page.

Print (All images in folder/Only selected images)
This control lets you specify whether to print all the images in the folder or just the ones that are currently selected.

When you are ready, click OK to start printing or Cancel to return to the Printer Setup dialog box.

Deleting image files
To delete all of the currently selected files in the folder, click the Delete button. After requesting confirmation, Picture Window will delete the image files and refresh the display.

Refreshing the Display
If you have reason to believe that files may have been added to or deleted from the current browse folder since you last selected it, you can bring the display back up to date by clicking the Refresh button.

Status Display
While images are being read to create miniatures, a status display just below the buttons at the top of the dialog box lets you know how many images have been processed so far -- when all the images have been read, it displays the total number of image files in the folder and the total file size in bytes.

Options
Clicking on the [image] button pops up an options menu you can use to customize the File Browse command:

Small Images/Medium Image/Large Images

This group of menu items let you select the size of the images displayed in the browse window. If you choose smaller images, more will fit on the screen at once, but the detail will be lower. At the smallest size, a small font is used and the file modification date is abbreviated to save space.

Save Browse Info in Folder

This setting toggles when you select it.

If the menu item is checked, then when the File Browse dialog box is closed, the miniature images and other information about the files in the folder will be saved in a file called PWBrowseInfo. While this does take up some disk space, it greatly speeds up the operation of the File Browse command the next time you browse the same folder. For obvious reasons, browse information is never saved for read-only folders such as folders stored on CD-ROM.

If the menu item is not checked, then no browse information is saved and any existing PWBrowseInfo file in the current folder is deleted. While this saves disk space, it means that every image file in the folder will have to be reread each time you browse the folder.

Sort by Name/Sort by Date/Sort by Size

This group of menu items let you select the order in which the miniature images are displayed -- alphabetical by name, by modification date, or by file size.


File Close

This command closes the current window. All memory and resources associated with the window are released.


File Revert

This command causes an image to be restored to the state it was in the last time it was saved or opened. Effectively, it reopens a file in the same window. This provides a convenient way to undo any painting, cloning, or other operations that you may have applied to an image using the freehand retouching tools.

The Revert command remains grayed out unless the current window has been modified usinge one of the freehand retouching tools.


File Acquire

This command is used to initiate the process of acquiring an image from a TWAIN-compatible input device (scanner, frame grabber, digital camera, etc.).

For instructions on operating the TWAIN driver, see the documentation that accompanies your input device.

Scanning Tips


Scanning Tips

Types of scanners

There are several kinds of scanners: film scanners, flatbed scanners, video capture devices, and drum scanners.

Film Scanners

This type of scanner is sometimes called a slide or transparency scanner. They are sepcifically designed for scanning film, usually 35mm slides or negatives, but some of the more expensive ones also scan medium and large format film. These scanners work by passing a tiny beam of white light through the film and reading the intensity and color of the light that emerges. The Photo CD scanning process works with a high quality film scanner.

Flatbed Scanners

This type of scanner is sometimes called a reflective scanner. They are sepcifically designed for scanning prints or other flat, opaque materials. These scanners work by shiningwhite light onto the object and reading the intensity and color of the light that is reflected from it. Some flatbed scanners have available transparency scanning adapters, but for a number of reasons these are not very well suited to scanning film.

Video Frame Grabbers

This type of scanner uses a video camera to capture a scene or object and then converts the video signal that comes out of the camera to a digital image in your computer memory. Video camera can be be used to capture 3-dimensional objects, but usually have much lower image quality that film or flatbed scanners.

Drum Scanners

These professional devices are pretty much out of the reach of the individual photographer. To use a drum scanner, the original is taped to a rotating clear plastic drum and scanned as the drum rotates. Drum scans have the highest quality but are labor intensive and very expensive.

CCDs vs Photomultipliers

Most film scanners, flatbed scanners, and video cameras use light sensing elements called CCDs (Charge Coupled Devices) to measure light. CCDs are relatively inexpensive, compact, and efficient. Most high end drum scanners use photomultiplier tubes to measure light. Photomultipliers, while larger and more expensive to design around, do offer superior dynamic range. Thus a scanner that uses photomultiplier tubes can extract more detail from very dark shadow areas of a transparency. CCD scanners, while steadily improving in this area, are still prone to losing detail in deep shadow areas.

Scanner Resolution

The amount of detail captured in the scanning process is determined primarily by the resolution of the scanner. Transparency scanners normally require much higher resolution than reflective scanners because film is so much smaller than a print. The more pixels the scanner captures, the finer the detail it can reproduce. Scanner resolution is usually reported in dots per inch (dpi).

Optical vs. interpolated resolution

Most film and flatbed scanners operate at a specific resolution called their optical resolution. This resolution is determined by the mechanical and optical characteristics of the scanner (such as the spacing between its individual CCD elements). The scanning software that comes with the scanner usually can create higher resolution scans by interpolating between the actual scanned pixels. This technique (which is analogous to that used in Picture Window's Resize transformation) does not actually add any new image detail, however. And, to make matters worse, the resulting files are much larger and thus more difficult to work with. Therefore, it is almost never worthwhile to scan at a resolution higher than the optical resolution of your scanner.

How to decide what resolution to scan at

The best way to determine what resolution to scan at is to work backwards from the print you want to produce. For most purposes, you will need between 100 and 300 pixels per inch to make a photographic quality print. At the low end of that range, the results will be noticably soft -- between 200 and 300 dpi the improvement is quite small. Thus to make an excellent quality 4x5 print, assuming a resolution of 200dpi, requires an image that contains roughly 800x1000 pixels (or more). When scanning to make a print of this size, you should thus adjust your scanner resolution accordingly, although scanning above the optical resolution of your scanner is not recommended (see above). The actual dpi that you scan at will depend on the size of the original. If you are using a flatbed scanner and are scanning a 4x5 original, then you would scan at 200dpi; if the original was smaller, you would need to scan at a higher dpi to get an image of the same size, and if the original was larger, you would scan at a lower dpi. Just pay attention to the image size in pixels.


File Select Source

This command is used to select a TWAIN-compatible input device (scanner, frame grabber, digital camera, etc.), if you have more than one device installed on your computer. This command displays a menu of the available TWAIN image sources; choose the one you want to use and then click OK.

Picture Window supports both 16-bit and 32-bit TWAIN drivers.

For details on operating the TWAIN driver, see the documentation that accompanies your input device.


File Print

This command prints the current image on any Windows-compatible graphics printer. If you output to a black and white printer, the image will automatically be converted to black and white during the printing process. Due to differences in the way color images are displayed on the screen and the color printers generated hard copy, it can be very difficult to get a good match between the picture you see on the screen and what comes out of the printer.

When you execute the Print command, Picture Window first displays the standard Windows Print dialog box. Use this dialog box to select the printer you want to use and options such as the resolution and number of copies you want printed. To select portrait vs. landscape printing or to select a particular printer or printer option, click the Setup button. When you are ready to proceed, click OK. At this point Picture Window displays its Print Dialog box.

The Print Dialog contains the following controls:

Page Preview

A page preview area occupies the lower right corner of the dialog box. The page preview area displays a scaled down representation of the output page as it will be printed so you can check the size and orientation of the image.

Caption

Whatever text you enter into the caption control is printed in the upper left hand corner of the page.

Page Size

The size of the output page is displayed in inches.

Image Size

The size of the image as it will appear on the page is displayed in inches.

Scale

This Popup List Control lets you select how you want the image scaled.

to image dimensions

Selecting this option causes the image to be printed at the size implied by its resolution (dpi) setting. This is the size displayed in the Window Info and Resize Transformation dialog boxes. If this size exceeds the area of the page between the current margins, the image is automatically scaled to fit page (see below).

one to one

Selecting this option causes the image to be printed at the the printer resolution, regardless of the resolution (dpi) setting of the image. Using this option one pixel in the image equals one pixel on the printer. If the resulting image size exceeds the available print area between the current margins, the image is automatically scaled to fit page (see below).

to fit page

Selecting this option causes the image to be scaled as large as possible to fit the space between the current margins.

In no case are the proportions of the image altered. The location of the image on the page can be controlled by adjusting the margins and horizontal and vertical alignment. For example, to move the image to the right, increase the left margin and set Horizontal Alignment to Left.

To create multi-image page layouts, first use the Layout Transformation to create a single image at the desired resolution and then print the composite image using the Print command.

Orientation

This Popup List Control lets you optionally print the image rotated 90 degrees. If you select Normal, the image is sent to the printer unrotated. If you select Rotated, the image is rotated 90 degrees and printed on its side. This setting is useful for printing images that have landscape proportions on printers with a portrait page orientation. Altrenatively, you can select Landscape orientation in the printer setup dialog box and print unrotated.

Horizontal and Vertical Alignment

These Popup List Controls settings let you control where the image is printed if it is smaller than the printable area (the available space between the left and right or top and bottom margins). Horizontal Alignment lets you line up the image with the left edge, the center, or the right edge of the printable area. Vertical alignment lets you line up the image with the top edge, the center, or the bottom edge of the printable area.

Margins

These four controls let you enter the left, right, top, and bottom margins in inches. The initial values for the margins are the minimum values that the printer supports based on how close to the edge of the paper it can print. If you attempt to set any of the margins to values smaller than these, they will be revert automatically to these minimum values.

Tiling

The Tile controls let you print images larger than a single page by breaking them into rectangular sections called tiles. The final image is assembled by trimming and mounting multiple pages together into a single, large composite. You can print images very large using this method (up to 20 by 20 tiles) as long as you have the patience and the paper, and a reliable printer.

The Horizontal Tile setting specifies how many pages wide to print and the Vertical Tile setting specifies how many pages tall to print. Guide lines are displayed on the page preview image to show the page boundaries. Once you start printing, the image is automatically broken up into tiles and each one is printed on a separate page.

The overlap between tiles is controlled by the Overlap setting. With overlap set to zero, adjacent tiles will just fit together if they are trimmed perfectly at the edge of the image. Setting a larger overlap value leaves you some room for error when trimming the edges.

When you are ready to start printing, click the OK button, or click the Cancel button to exit without printing.

Print Pages

When printing a tiled image, it may be necessary to reprint a subset of the pages if a printer error occurs. The Print Pages setting lets you specify a range of pages to print – any pages outside of this range are not output.

Printing images of a specific size

There are three techniques for printing an image of a specific size. In any case, the first step is to crop the image to the desired proportions.

1) Set the Scale control to fit to page and adjust the margins until the image size readout indicates the desired size. This is the preferred method

2) Use the Resize transformation to resize the image to the desired dimensions while preserving the File Size and Proportions. Then set the Scale control to to image dimensions and print.

3) Use the Resize transformation to resize the image to the desired dimensions using the printer's resolution in dots per inch while preserving Proportions. Then set the Scale control to one to one and print.

Printing images at a specific location on the page

To position the printed image off center on the page, set different left/right or top/bottom margins.

Printing Tips


Printing Tips

About printers

To get the best results from your printer, you need to understand something about how in converts images into hard copy. There are two types of printer -- continuous tone printers and those that print only a limited number of colors (typically cyan, magenta, yellow, and black).

Continuous Tone Printers

Continuous tone printers are capable of laying down minute dots each of which can be any color. These printers can produce images that are photographic or near photographic in appearance. The most common type of continuous tone printers are dye sublimation printers, but there are a number of other continuous tone technologies as wel.

Halftone Printers

Halftone printers can produce dots that are only one of three or four colors. To reproduce photograph which contains a full range of colors, these printers must output clusters of dots whose average color approximates the color of the image. This process of rendering an image using a limited palette is called halftoning or dithering and there are many techniques for doing this, each of which has its own distinctive appearance and strengths and weaknesses. The most common techniques are error diffusion which creates a random pattern of dots, classical halftoning which is the technique most commonly used with printing presses, and Bayer halttoning. Halftone printing technologies include laser printers, ink jet printers, thermal wax printers, and others.

Printer Resolution and Print Quality

Because halftone printers must perform dithering to reproduce a full range of colors, they must print at a higher resolution (dots per inch) to achieve results comparable to a continuous tone printer.

To achieve photographic output from a continuous tone printer generally requires printing at a resolution of somewhere between 100 and 300 dots per inch. Images printed at 100 dots per inch will be visibly soft; at 150 to 200 dots per inch they will be quite good, and beyond 300 dots per inch there is little or no visible improvement.

To achieve roughly equivalent quality from a halftone printer requires about 5-10 times higher resolution. Thus a 720 dot per inch ink jet printer is roughly equivalent to  a 75-150 dot per inch continuous tone printer.

Perceived image quality will vary considerably with subject matter as different printing technologies are better at reproducing different kinds of images. Just at different conventional photographic printing papers and techniques each have their own character, so do computer printers.

Image Resolution and Print Quality

To get the best quality images from your printer, you need to send it images with sufficient resolution. For the best possible quality from a 300 dpi continuous tone printer, you will need to send it 300dpi image data. Thus to make a 4x5 inch print, the image should be 1200x1500 pixels. (This is computed by multiplying the resolution in dpi by the image size in inches.). An image of this size contains 1.8 million pixels (1200 times 1500) and, since each pixel requires 3 bytes of memory, this is a 5.4MB image. While this will give the best possible results, very good results can still be obtained with smaller image files.

To get the best quality from an ink jet or other halftone printer, you will need an image resolution of roughly 1/4 to 1/3 of the printer resolution. This is because the printer must use a cluster of dots to represent each pixel. Thus for a 720 dpi ink jet, you will only need roughly 200 dpi of image data. Supplying the printer with more image resolution than this does not yield a noticable improvement in quality. Again, good results can also be achieved working with lower resolution images.


File Print Setup

This command brings up the standard Windows Print Setup dialog box which you use to select a printer and print options.


File Slide Show

The slide show command lets you create a set of compressed image files that can be viewed as a slide show using the Picture Window Slide Show Viewer application, a separate program for Microsoft Windows that you can freely distribute to others along with your images.

When you start the slide show command, Picture Window displays a single, blank slide.

Image Size

At the top of the Slide Show dialog box is a control you can use to set the dimensions of images in the slide show in pixels. If you select a small image size, you can fit more slides on a disk; if you select a larger size, there will be more detail in each slide. You can adjust this setting as you build the slide show and make some images larger than others. The slide show viewer application can zoom and scroll images, so screen size is not a limitation on the image size. Images whose dimensions are larger than the size you select are resized before being saved as part of the slide show; images that are already smaller than the selected size are not resized.

Quality

At the top of the Slide Show dialog box is a control you can use to set the quality of images in the slide show. The lower the quality you select, the more slides will fit on a disk; the higher the quality, the better images will look, especially when the viewer zooms in to examine details. You can adjust this setting as you build the slide show and make some images higher qulaity than others.

Duration

At the top of the Slide Show dialog box is a control you can use to set the number of seconds each slide will be displayed. You can override this global setting on a slide by slide basis by setting individual slide properties (see below).

Save with

This control lets you specify whether you wish to include a copy of the slide show viewer with your slide show. You have three options: no viewer, installable viewer, and runable viewer. If you include a copy of the viewer, the installable version, while slightly smaller, requires the recipient to install the viewer before using it; the runable version can be executed directly from the slide show disk but takes up a little more space on the disk. The size of the viewer is reflected in the Total Size control (see below).

Total Size

The total size of the slide show in megabytes is displayed at the top of the Slide Show dialog box. If you will be writing the slide show to a floppy disk, you should monitor this number and keep it a little below the capacity of the disk. If you want to save more images than will fit on a single disk, you must create multiple slide shows.

To create the first slide, double-click on the blank slide. This will bring up a File Open dialog box which you then use to select an image file. Once you select the file, Picture Window reads it in, resizes it, saves it as a temporary JPEG file, and displays a thumbnail image on the screen. The last slide displayed is always blank and is used as a placeholder to create new slides. Temporary files are created in the temporary file directory.

To change the order of the slides in the slide show, simply drag and drop a slide to its desired position - the slide is inserted where you drop it and the following slides are moved one position to the right.

To insert a new slide, double click on the last slide (which is always blank) and then drag this new slide to its desired position.

To delete a slide from the slide show, select the slide by clicking on it and then click on the Delete Slide button.

To replace a slide with a different file, first click on it to select it and then click the Edit button (as a shortcut you can simply double-click on it) and select a new file.

To enter a caption for a slide, select the slide by clicking on it and then enter the caption text into the edit control at the top of the slide show dialog box.

To enter a description for or add a sound to a slide or to set a specific length of time for a slide, select the slide by clicking on it and then click on the Properties ... button at the top of the slide show dialog box. This will pop up a window in which you can enter as many lines of text as you want describing the slide up to a total of 32,000 characters. You can also specify a WAV file to be played whenever the slide is displayed, play the sound to verify that it's the right one, or reset the sound for a slide. To make the sound loop continuously while its corresponding slide is displayed, click on the Loop checkbox. Finally, you can enter in a slide duration in seconds -- enter zero if you want the duration to default to the overall slide show delay time. When you are done, click the OK button to close the description window.

To create the slide show disk (or directory), click the Save As ... button. This displays a standard Windows File Save dialog box. You can save slide shows in either of two different formats -- Slide Show (.ss) or AVI (.avi). Select the desired file type and where you want the slide show to be copied by specifying the slide show overview file which must have the extension .ss or the AVI file which must have the extension .avi, and then click Save.

Slide Show FIles

If you save as a Slide Show file and the appropriate option was selected, Picture Window first transfers a copy of the installable or runnable slide show viewer to the slide show directory. Finally, overview file, thumbnail files, and slide files are copied to the slide show disk.

If a slide show of the specified name already exists, Picture Window will ask you if you want to delete it. Answering Yes will delete all the files in the preexisting slide show.

To create a slide show floppy that runs automatically, save your slide show with the name "AUTOPLAY.SS". When the slide show viewer starts up, it automatically searches for a slide show of that name on the floppy disk in the A drive. If it finds the file, it plays the slide show in auto-advance mode.

To control the slide show viewer preferences for the autoplay slide show, first configure the slide show viewer as you want it and then exit the viewer. Finally, copy the file "VIEWER.SES" from your Windows directory to the floppy disk. This file contains the slide show viewer preferences.

To make it impossible for the person viewing the slide show to modify the preferences settings (time delay, background color, etc.), open the VIEWER.SES file in Notepad or some other text editor and insert a line that reads:

lockout 1

just before the last line which should read:

end

AVI Files

If you save as an AVI file, an additional dialog box will be display by Windows which offers you choices of video compression schemes, depending on which drivers are installed on your system -- or you can select Uncompressed to bypass compression. Depending on the compression scheme you select, addition options such as compression ratio may be displayed. The current slide size is used to define the AVI frame size, so you should select this setting before you click the Save As button. Once you click OK, the images in the slide show are compiled into an AVI file and written out.

Slide shows saved as AVI files play back like a video clip with each still image displayed for a length of time equal to its duration as entered in the properties dialog box (see above). If no duration is entered, the global duration setting is used (see above).

Relative advantages and disadvantages of AVI vs Slide Show Format

Saving slide shows as AVI files has several advantages. First, AVI files are a Windows standard. This means that they do not require a viewer since support for playing AVI files is built into Window (just double-click on an AVI file's icon to play it). AVI files are also supported by most web browsers and can be exported to many other Windows programs. Secondly, the AVI file encapsulates the entire show into a single file which is more convenient to store and transmit. Third, you completely control the pacing and playback of the slide show as the person who plays the AVI file cannot change any of its settings. Finally, AVI files can be enhanced edited using programs such as Adobe Premiere.

The disadvantages of saving slide shows as AVI files are that you cannot reload an AVI file into Picture Window, control the playback rate or play the slide show manually as you can with the slide show viewer, there is no support for captions, and the image quality on 256-color displays is not as good as that achieved using our slide show viewer.

To load an existing slide show, click the Load ... button. This operation deletes all current slides, if any, after issuing a warning. Select where you want to copy the slide show from by specifying a pathname of overview file. The slide show overview, thumbnail, and slide files will be loaded from the specified location. Only slide shows saved as Slide Show files can be loaded -- loading AVI files is not supported.

To print a summary of all the slides in a slide show, click the Print Summary button. This first displays a standard Windows Print Setup dialog box so you can select and configure the printer you want to use to print the summary. As soon as you click OK, the slide show summary is automatically printed. The summary consists of one or more pages of numbered miniatures of each image in the slide show and their captions (if any).

To exit, click the Exit button. At this point all temporary JPEG files that have been created are automatically deleted. If the current slide show has been modified you will be offered a chance to save it before exiting.

Slide Show Tips


Slide Show Tips

Selecting Image Size and Quality

For best viewing on a screen of a given size, choose the next smaller image size. This will make the images display as large as possible without the viewer having to zoom the images. Making the slides a little smaller than the screen leaves room for the window caption, menu, borders, and buttons.

The lowest quality setting is normally perfectly fine for on-screen viewing at 1:1 although artifacts will usually be noticable when the image is zoomed in. The middle setting normally produces images that look OK even when zoomed in.

You can get more images on a slide show disk if you choose a smaller image size though this will give you less image detail. You can get more detail in each image by choosing a larger image size but you will get less images on a disk. If the images are larger than the window in which they are being viewed, they can be zoomed to reveal additional detail.

Making the Slide Show fit on a single floppy disk

To make sure your slide show fits on a single disk, keep track of the total size readout as you build the slide show. A blank 3.5" floppy disk holds around 1.44MB of data.

Temporary Files

As you construct a slide show, Picture Window creates temporary JPEG files to hold copies of each slide's image and thumbnail. These files are created in the Startup Directory specified in your File Preferences. If no Startup Directory is specified, the temporary files are created in the root directory of your C drive.

You should make sure you have enough free space on whatever drive will hold the temporary files. These files are named temp*.t and temp*.s; normally they are automatically deleted when you exit the Slide Show command, but if Picture Windows somehow exits abnormally, these files can be left behind, in which case you can safely delete them yourself.

Slide Show Dialog


File Preferences

This command lets you view and modify a number of settings that affect Picture Window's overall operation. These settings can be changed for the current Picture Window session only, or they can be saved and used for future sessions as well.

Workspace Color

This Color Control lets you set the color of the workspace background against which images are displayed. A dark gray is a good choice for this option; avoid bright colors as they can influence your color perception.

Border Color

This Color Control lets you set the color of the border that is displayed around each image. White is usually the best choice for this color as it provides a reference white against which you can judge the brightness of the image.

Border Width

This control lets you set the width of the image border in pixels. A value of zero will eliminate the border entirely.

Confirm on Close

If you want Picture Window to ask for confirmation before it closes image windows that have been modified but not yet saved, select yes; otherwise select no.

Resolution

The resolution setting is the default image resolution that will be used for images. This number has no effect on the image itself; it is merely a conversion factor between pixels and inches. You can change the resolution of an image with the Resize Transformation.

Length of File List

This setting controls how many of the most recently opened files are listed at the bottom of the File menu. When running Picture Window at a resolution of 640x480, there is only room for about 4 filenames. At higher resolutions, you can increase this number up to a maximum of 10.

Undo

This setting affects the behavior of undo for the clone, paint, and miscellaneous retouching tools. You can select none, single level, or multilevel. The more undo levels you enable, the more strokes you can erase and the more memory the undo buffers will occupy. Multilevel (the default setting) is strongly recommended as this permits unwinding the operation of each tool all the way back to the start of its use. None disables a useful feature of the Clone tool whereby the undo buffer is used to improve its behaviour when the area being cloned overlaps the area being cloned from.

PhotoCD Directory

If this setting is left blank, Picture Window will attempt to locate your CD-ROM drive automatically. If your CD-ROM drive is on a network, if you have more than one CD-ROM drive on your system, or if your CD-ROM drive cannot be located automatically for some other reason, enter the location of your CD-ROM drive here. For example, if your PhotoCD drive letter is X, enter X:\.as your PhotoCD directory. To select the directory graphically, click the Browse... button just to its right.

Startup Directory

If you leave this blank, Picture Window will start looking for image files in the current directory. If you enter the name of a directory, then that directory will be used first. To select the directory graphically, click the Browse... button just to its right.

Temporary File Directory

Certain Picture Window commands need to create temporary files. If you want these files to be created in a specific directory (because you know there is free space on a particular disk for example), then enter the name of that directory here. If you leave this entry blank, temporary files will be created in a directory called C:\TEMP. To select the directory graphically, click the Browse... button just to its right.


File Associations

This command lets you create or remove file associations for Picture Window. When you create an association between files of a given type and Picture Window, you can open the files from within Windows Explorer or My Computer simply by double-clicking on them. Also, files associated with Picture Window are displayed with the Picture Window icon.

Since you may have a number of different image editing programs installed on your computer, this command lets you specify which file types you want to open with Picture Window. Picture Window creates associations only at your request – by default no associations are created when Picture Window is installed on your computer.

File associations are based on the file’s extension. For each file type listed in the dialog box, the corresponding file extension(s) are also listed.

To create one or more associations, check the boxes next to the file types for which you want to create associations and then click the Add button.

To remove one or more associations, check the boxes next to the file types whose associations you want to remove and click the Remove button. Removing an association does not automatically restore any previous associations to other programs. To do this you must reinstall the application or, if it has a command similar to File Associations, you can re-establish the association manually.

The Select All and Select None buttons are shortcuts for checking or unchecking all the boxes at once.


File Calibrate

This command lets you calibrate you monitor to a standard condition (Gamma 2.22).

Caution: For critical applications, do not run Picture Window using a flat panel display (liquid crystal or active matrix) such as are found on some color notebook computers. These display panels have different characteristics from monitors and can give rise to color matching errors when you make prints. In addition, these characteristics tend to vary considerably based on your viewing angle, making it difficult to obtain consistent results.

Note: Certain display adapters (e.g. certain Matrox models) can set color temperature (white point) and gamma, typically via settings in the Windows Control Panel. If your display adapter has this feature, use it to adjust these settings before calibrating. Set the white point to a color temperature of 5000 degrees and the gamma to 2.22. Settings made in this manner are applied to all the programs you run on your computer. The calibration performed by Picture Window is specific to Picture Window and does not affect other programs. If you set the white point using the Control Panel, make sure you set the white point within Picture Window to pure white to avoid making a double correction. You can then use Picture Window’s calibration curves to fine tune the gamma adjustment, if desired.

Before calibrating:

Let your monitor warm up for at least ten minutes.

Establish good viewing conditions.

Make sure your display adapter is set to 24-bit colo r (16 million colors) if possible, and that the dither setting in the File Preferences Dialog is set to none. If your display adapter does not support 24-bit color, then set it to use 16-bit (32,000 or 64,000 colors). Calibrating you monitor in 256-color mode is not recommended.

There are three steps to calibrating your monitor:

 Setting the brightness control

 Setting the calibration curve

 Setting the monitor white point

When you are done, click OK to save the calibration settings.


Setting the brightness control

When you click on the [image] button on the File Calibrate Dialog, Picture Window displays a reference image against a black background.

Start by turning your monitor's contrast control all the way up.

Next, adjust your monitor's brightness control until the image looks natural. If the image appears washed out and the black background starts to turn gray, the brightness control is set too high. If the image starts to become murky, the skin tones look too dark, and shadow detail disappears, the brightness control is set too low.


Setting the calibration curve
Setting the calibration curve (gamma curve)

When you click the [image] button on the File Calibrate Dialog, Picture Window displays five gray patches above a white rectangle and a curve. To set the calibration gamma curve, you will need the film overlay that came with your Picture Window software.

Most uncalibrated PC monitors conform to a curve that corresponds to a gamma of roughly 2.2-2.4. The gamma curve defines how the brightness of the display varies as a function of the pixel values in the image. A gamma value of 2.22 means that the brighness of the display is proportional to the pixel values raised to the 2.22 power. Since this corresponds quite closely to the response of the human eye, using a gamma of 2.22 ensures that equal steps in pixel values produce roughly equal steps in perceived brightness. Gamma values of 2.22 are the video standard in the television industry and are used in PhotoCDs. In the prepress industry, a gamma of 1.8 is commonly used as this corresponds more closely to the characteristics of printing presses. Images created to look natural on a monitor calibrated to a gamma of 1.8 will look too dark on a monitor set to gamma 2.2. For some reason, the normal gamma value used on Macintoshes is 1.4. For this reason, images created on Macs often look much too dark on PCs. Picture Window always calibrates to a gamma of 2.22.

Before your start

The calibration dialog has five numbers displayed across the top (the optical densities of its five gray patches). If those number are different from the numbers printed on the envelope containing your overlay; enter the numbers from the envelope in the boxes.

Tape the overlay (dark square on the left, light square on the right) to the face of your monitor over the white rectangle. Then adjust the position and size of the Monitor Calibration Dialog to line up the gray patches next to the corresponding gray squares on the overlay.

The goal of the calibration process is to get the gray patches to look the same as the gray squares of the overlay.

Adjust the brightness of each patch by dragging the corresponding point on the curve up or down.

To adjust the color of a patch, click on it to bring up a color picker. Choose a color for each patch to match the square in the overlay. Tip: If a patch has a noticable color cast, then set the color picker to the complementary color. For example, if a patch is too green, then move the selection point in the color picker toward the opposite side of the color wheel (magenta). The further you move the point off center, the stronger the effect.

You may need to go back and forth several times between adjusting the brightness and color of each patch to get a good match.

As you work, check the curve display - the final calibration curves should be smooth. If there are kinks in the curve, go back and check the settings for the corresponding gray patches. If the curve deviates greatly from a diagonal line from the lower left to upper right corner, try adjusting the monitor brightness control again and then try again.


Setting the monitor white point

When you click on the white button on the File Calibrate Dialog, Picture Window displays a large white rectangle and a color picker. If you have a daylight-corrected light box, place it next to your monitor as a white reference. Otherwise, you can hold a piece of white paper up to the screen and illuminate it with the same kind of light you expect to view your prints in. Then use the color picker to adjust the color cast of the white rectangle to more or less match the white of the light box or paper. This adjustment is not particularly critical, but you do need to set a slightly yellow white point to neutralize the natural blue cast of most computer monitors.

If your monitor or display adapter has settings or comes with software to adjust the white point of your monitor, use these to adjust the color temperature of your monitor to roughly 5000 degrees or to match a light box or sheet of white paper. Then set the white point to pure white within Picture Window to avoid correcting the monitor twice.


File Exit

This command terminates a Picture Window session.


Edit Undo

This command reverses the action of the last cloning, painting, or miscellaneous tools operation you performed. For the undo feature to be active, the undo setting in File Preferences must be set to single-level or multilevel.


Edit Undo All

This command reverses the action of the last session of cloning, painting, or miscellaneous tools operations you performed. For the undo all feature to be active, the undo setting in File Preferences must be set to multilevel.


Edit Copy

This command copies the current image to the Windows clipboard. This is a convenient way to move an image between different Windows applications without having to save it first. The image is stored on the clipboard in DIB (device independent bitmap) format; any program capable of accepting clipboard data in this format will be able to paste the image into its own documents.

To create a second copy of an image within Picture Window, use the Copy transformation instead of Cut and Paste.


Edit Paste

This command pastes whatever image is currently on the Windows clipboard into a new image window. For this command to be active, an image in DIB (device independent bitmap) format must be present on the clipboard.


Window Info

This command pops up a window which displays information about the current image:

The image type (color, black and white, binary, 16-bit black and white, or 48-bit color)

The image size in bytes

The image width and height in pixels

The image width and height in inches

The image resolution in dots per inch

The image file pathname (if any)

The image file type (if any)

The date the file was last modified (if available)

Image Basics


Window Count Colors

This command examines each pixel in the current image and computes the number of different colors or gray levels it encounters. The result is then displayed in a dialog box.

Note: this command can take a very long time to execute if the image is large or contains a large number of different colors, but you can interrupt it at any time by clicking the Cancel button next to the progress indicator.


Window Grid

Grid

If you select a grid value larger than 1, a grid with that many divisions is displayed over the current image. Setting the grid value to 1 clears the grid. The grid does not make up part of the image, it is used for display purposes only. As you change the grid setting the grid updates immediately so you can see what the grid will look like.

Click OK to establish the new grid setting; click Cancel to revert to the previous grid setting.

Each image window can have its own independent grid setting. Grids can be useful to help you locate or align elements within an image precisely.


Window Blink

This command lets you compare two windows by lining them up and rapidly switching between them. Features that are the same in both images will remain fixed while those that differ between the two images will blink.

Start/Stop

These two colored buttons start and stop the blinking. When you click the [image] button, the second image is moved so that its upper left corner coincides with the upper left corner of the first image and the alternating display of the two images is initiated. When you click the [image] button, the second image's position is restored and the display is returned to normal.

Images

These two Color or Image Controls let you specify the two images to be compared.

Rate

This control lets you set the blink rate. You can change the blink rate even while blinking is in progress.


Window No Tool Bar

This command hides the tool bar, leaving a little more room for the workspace.


Window Tool Bar at Top

This command causes the tool bar to be displayed at the top of the workspace.


Window Tool Bar at Left

This command causes the tool bar to be displayed at the left of the workspace.


Window Expand

This command adjusts the current image window by zooming it in as far as possible while still letting the entire image fit on the screen.


Window Fit

This command shrinks the current image window, removing any excess image border. If the entire image does not fit on the screen, it is zoomed out until it does.


Window Zoom In and Resize

This command zooms the current image window in and increases the window size at the same time, unless doing so would make it too large for the entire image to fit on the screen.


Window Zoom In

This command zooms the current image window in, leaving the window size unchanged.


Window Zoom Out

This command zooms the current image window out., shrinking it if necessary.


Window Zoom Factor

This command lets you enter a specific zoom factor. You can choose either a magnification or reduction ratio.


Window Zoom to 1:1

This command sets the current image window to a 1:1 zoom factor.


Window Next

This command cycles through all the windows in the workspace, bringing the next one to the top each time the command is executed.


Window Arrange Icons

This command arranges the icons for any minimized image windows in a row at the bottom of the workspace.


Window Cascade

This command arranges the open windows in a cascaded configuration. This can be useful when you have a large number of open windows and are having trouble locating one of them.


Window Close All

This command closes all windows in the workspace.


Transformation Convert

Using Transformations

This transformation converts an image from one type to another.

Binary images are made up of 1-bit pixels of only two colors, black and white.

Black and White images are made up of 8-bit pixels that can be any of 256 different shades of gray.

Color images are made up of 24-bit pixels that can be any of more than 16 million different colors.

Note: 16-bit black and white and 48-bit color images described below are supported only by the Pro version of Picture Window

16-bit Black and White images are made up of 16-bit pixels that can be any of 65536 different shades of gray.

48-bit Color images are made up of 48-bit pixels in which each component has a range of 0..65535.

The Convert Dialog has the following controls:

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Convert From

This control displays the type of the input image (Binary, Black and White, Color, 16-bit Black and White, or 48-bit Color).

Convert To

This Popup List Control lets you select what type of output image you want to convert the input image to -- Binary, Black and White, Color, 16-bit Black and White, or 48-bit Color. If the types of the input and output images are the same, the transformation simply makes a copy of the image.

When converting from an input image to an output image that has more bits per pixel, the result image is visually identical to the input image (but takes up more memory). When reducing the number of bits per pixel, the following methods are used:

To reduce from color to black and white, the luminance of the pixel is computed. For other methods of reducing from color to black and white, see the Monochrome Transformation or the Extract Channel Transformation.

To reduce from black and white to binary, any pixel brighter than a 50% gray is made white and any pixel darker than 50% gray is made black. For more powerful conversions to binary, see the Halftone Transformation .


Transformation Filter

Using Transformations

This command simulates viewing the current image through a colored filter. The colored filter can either be a solid color or it can be any color image whose width and height in pixels are the same as those of the input image. In either case the result is like sandwiching two transparencies and photographing the result.

The Filter Dialog has the following controls:

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the filter transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Filter

This is a Color or Image Control which lets you select the filter color or image.

You can use the Gradient transformation to create a custom graduated neutral density or color filter image the same size as the input image.

Complement

Clicking this checkbox causes the filter color or color image selected in the Filter control (see above) to work as though it were replaced by the complementary color. Thus, to remove red from an image, instead of having to select a cyan filter (cyan being the complement of red), you can simply select a red filter and then click on the Complement checkbox. The more saturated the red color you select, the more red will be removed from the input image.

Method

This Popup List Control lets you select what type of filtering you want to perform:

Additive filtering produces the effect of sandwiching the input image with the filter color or image and viewing them on a light box. The net result is that wherever the input image is white the result image takes on the filter color and wherever the input image is black, the result image is also black. Mathematically, filtering is done by multiplying the two image together.

Subtractive filtering is analogous to sandwiching two negatives together and then taking a negative of the result. The net result is that wherever the input image is black the result image takes on the filter color and wherever the input image is white, the result image is also white. Mathematically, subtractive filtering is done by inverting both the input image and the filter, multiplying them together, and then inverting the result.

Exposure Compensation

This slider lets you compensate for the tendency of some filters to darken the input image. The larger the compensation factor you choose, the brighter the result image will be. The slider is calibrated in f stops; in other words each increase of 1.0 on the slider readout corresponds to brightening the image by a factor of two. Be careful not to select to high an exposure compensation value or the resulting image may lose highlight detail.

Lightening and Darkening

Vignetting


Transformation Composite

Using Transformations

This transformation combines an overlay color or image with the current image; it can create a range of effects from simulating multiple exposures to complex compositing operations like placing an object in one image behind an object in another.

The Composite Dialog has the following controls:

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

The resulting composite image is always the same size as the input image. If you want to create a composite that extends beyond the edges of the input image, start by using the Add Border transformation to make some extra room.

Amount

The amount control lets you control how much of the composite transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image. This can be used to composite an object from the overlay image "behind" an object in the input image by protecting the object with a mask.

Overlay

This is a Color or Image Control which lets you select the overlay color or image.

If you select a solid color, then that color is applied as a semitransparent overlay over those parts of the input image not protected by the amount mask. Picture Window will not let you enter an overlay amount mask or set alignment points.

If you select an overlay image, you can use an overlay amount mask to control what parts of the overlay image are painted over the input image and the transparency of the overlay image. This mask can be used to isolate an object in the overlay image and composite just that object over the base image. You can also reposition, rotate, scale, and even shear the overlay image to precisely align specific points in the overlay image with corresponding points in the input image.

Operation

This Popup List Control lets you select how the overlay color or image is combined with the input image.

If you select Blend, then the overlay image is blended with the input image with a transparency determined by the amount and overlay amount controls.

If you select Lighten, or Darken, then the overlay image is blended with the input image, but only where it lightens or darkens the input image.

If you select Filter, then the overlay image is applied to the input image as a filter (similar to the way the Filter transformation works). This differs from a blend which is analogous to a double exposure while filtering is like sandwiching two transparencies. Note that dark parts of the overlay image are opaque and light areas are transparent as opposed to subtractive filtering (see below).

If you select Subtractive Filter, then the overlay image is applied to the input image as a subtractive filter (computed as the negative of filtering the negative of the base image with the negative of the overlay image). This is similar to the normal (additive) filtering except that light areas of the filter are opaque and dark areas transparent.

If you select Negative, then a special effect is created where the overlay and input image are combined so as to reverse each other.

If you select Add, then the overlay image is added to the input image; if you select Subtract, the overlay image is subtracted from the input image. Add and Subtract can generate out-of-range pixel values (outside the range 0..255) which are then truncated. Absolute Difference is similar to Subtract except that negative differences (i.e. where the overlay image is brighter than the base image) are converted to positive instead of being truncated to black.

If you select Register, then the overlay image is blended with the input image with a transparency determined by the amount and overlay amount controls, but the areas of the input image which are not covered by the overlay image show up as black in the result image.

Alignment

This Popup List Control lets you select how the overlay image is aligned with the input image. Unless alignment is set to none, numbered alignment points are displayed over the input and overlay images. You can drag these points to position them -- to move all the aligment points at once, hold down the Shift key while moving the cursor. A box is also displayed over the input image which shows where the edges of the overlay image will fall.

If you select none, then the overlay image is placed directly over the input image with their lower left corners aligned.

If you select 1-point (shift), then the overlay image is shifted (without being scaled or rotated) so as to bring one point in the overlay image into alignment with one point in the input image.

If you select 2-point (shift/rotate), then the overlay image is shifted so as to bring control point 1 in the overlay image into alignment with control point 1 in the input image and the line between control point 1 and control point2 in the overlay image is aligned with the line between control point1 and control point 2 in the input image, thus shifting and rotating the overlay image without altering its size. Consequently, control point 2 in the overlay image is not necessarily brought into coincidence with control point 2 in the input image.

If you select 2-point (shift/rotate/scale), then the overlay image is shifted, scaled, and rotated as necessary so as to bring two points in the overlay image into alignment with two points in the input image.

If you select 3-point (shift/rotate/scale/shear), then the overlay image is shifted, scaled, rotated, and skewed as necessary so as to bring three points in the overlay image into alignment with three points in the input image. This type of warping is called an affine mapping.

If you select 4-point (perspective warp), then the overlay image is warped using a perspective mapping to bring four points in the overlay image into alignment with four points in the input image.

Note: The multi-point alignment feature described below is available only in the Pro version of Picture Window

If you select Multi-point, then the overlay image is warped using 3-point alignment (based on the first three alignment point pairs) with any additional alignment points up to a maximum total of 61 being used to make local corrections.

When Multi-point alignment is selected, a small toolbar is displayed just below the Alignment control to let you add or remove alignment points from the input image.

Clicking the [image] button activates Adjust mode -- this lets you adjust the locations of alignment points by clicking and dragging them. This is the default mode of operation.

Clicking the [image] button activates Add mode -- this lets you add a pair of alignment points by clicking on the input image window. An alignment point is created at the location of the cursor when you click on the input image, and a corresponding alignment point is also created in the overlay image based on the 3-point alignment currently in effect. You can then adjust the locations of these alignment points as necessary. Alignment points are numbered 1, 2, ... 9 and then a, b, ... z and finally A, B, ... Z.

Clicking the [image] button activates Remove mode -- this lets you remove a pair of alignment points by positioning the cursor over the alignment point in the input image window and clicking.

After inserting or removing an alignment point, the toolbar is automatically reset to Adjust mode to prevent accidentally adding or removing alignment points.

Several alternate multipoint interpolation methods have been implemented, namely: the Shepard method, the Hardy method, the Thin Plate method, and the Gaussian method. Each method causes all alignment point pairs to be matched, but they differ in how they treat the image inbetween alignment points. The multipoint interpolation method can be selected via the [image] button at the top of the Composite dialog box. The defualt method is Hardy which usually produces the smoothest result. If you select either the Hardy or Gaussian methods, an additional slider is displayed at the bottom of the dialog box. Smaller R values make the effects of each alignment point more local; larger R values make each alignment point affect a larger area.

As an aid in locating alignment points within the base and overlay image windows, especially when they are zoomed in to a high magnification, you can press the 1, 2, … 9 or a, b, ... z or A, B, ... Z key on the keyboard to recenter the image windows on their corresponding alignment points. For this to work, you must first select the Composite dialog window or the base or overlay image window before pressing the key. Both image windows will then be scrolled to make the specified alignment point as near the center of the window as possible (if the alignment point is near an edge or corner of the image, it may appear off-center).

The Refine button (located just below of the Alignment control) greatly simplifies the process of precisely registering two images of the same subject. When you click to button, Picture Window jigglesthe locations of each overlay alignment point so as to minimize the difference between the base and overlay images. Holding the alignment points in the base image fixed, Picture Window searches for the alignment point location in the overlay image up to 5 pixels from its original location that results in the closest match between the base image and the overlay image. For this to work, the base and overlay images must contain similar information around their alignment points, and you must set the initial locations of the alignment points manually to within 5 pixels of their optimal locations.

Mathematical Formulas

This section describes the mathematical formulas used to combine images, based on the Operation selected. The pixel value from the base image is v1; the overlay image pixel value is v2, and oamt is the Overlay Amount slider setting. The resulting pixel value is v.

Blend, Register

    v = v1*(100-oamt) + v2*oamt

Lighten

    v = max(v1, v1*(100-oamt) + v2*oamt)

Darken

    v = min(v1, v1*(100-oamt) + v2*oamt)

Filter

    v = v1*(100-oamt) + ((v1*v2)/255)* oamt

Subtractive Filter

    v = v1*(100-oamt) + (255-(((255-v1)*(255-v2))/255))* oamt

Negative

    v = v1*(100-oamt) + (v1 xor v2)*oamt

Add

    v = v1*(100-oamt) + min(255,v1+v2)*oamt

Subtract

    v = v1*(100-oamt) + max(0,v1-v2)*oamt

Absolute Difference

    v = v1*(100-oamt) + abs(v1-v2)*oamt

Once the result value, v, has been computed using the above formula, it is then combined with the pixel value from the base image, v1, depending on the value of the Amount slider, amt as follows to produce the final result, v’:

    v’ = v1*(100-amt) + v*amt

For RGB color images, the same computations are performed separately on each color component.

Composite Examples


Transformation Gradient

Using Transformations

This command generates an image the same size as the current image filled with a graduated sequence of colors. The gradient can be linear, oval, or rectangular; a linear gradient varies at a fixed angle across the image; an oval or rectangular gradient expands outwards from a central point. The color sequence can be specified by as few as two points, or it may include many intermediate colors at different locations along the gradient. You can also control the type of each transition from one color to the next.

You can also create a 4-Corner gradient which fills the output image inwards from its four corners, each of which may be specified as a different color.

Positioning the Gradient

You position the gradient by adjusting points that appear as an overlay on the input image.

For a linear gradient, you position the starting and ending point of the gradient line. Picture Window displays additional lines at right angles to the gradient line for reference purposes. The gradient colors are be painted in sequence perpendicular to the line connecting the starting and ending point. The starting color is painted beyond the starting point and the ending color is painted beyond the ending point.

For an oval or rectangular gradient, you position a box that contains the outermost oval of the sequence. The gradient colors are painted in ellipses or rectangles that grow outward from the center. The starting color is painted at the center and the ending color at the outermost ellipse or rectangle and beyond. When creating an oval or rectangular gradient, you can force it to be circular or square by holding down the Shift key while you drag one of the four edge control points.

You may position control points for linear, oval, or rectangular gradient outside the boundaries of the input image, and this is necessary to obtain certain effects where the gradient runs off the edge of the image. To do this usually requires enlarging the input image window by resizing it.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Type

This Popup List Control lets you select the type of gradient you want to generate: Horizontal, Vertical, Linear, Oval, Rectangular, or 4-Corner.

Horizontal, Vertical, and Linear gradients vary according to the color line in bands. You control the location and orientation of the linear gradient by adjusting control points displayed over the input image. You adjust the gradient colors and transitions using the color line control (see below). If you select Horizontal or Vertical, the control points are fixed to make a horizontal or vertical gradient that covers the entire image.

Oval and Rectangular gradients vary according to the color line in a series of ellipses or rectangles that grow outward from a central point. You control the location and size of the gradient by adjusting control points displayed over the input image. You adjust the gradient colors and transitions using the color line control (see below).

When you choose 4-Corner, the color line, cycle, and antialias controls (see below) are replaced by four color controls that let you specify the colors of each of the four corners of the output image. A 4-color gradient is interpolated smoothly into the interior of the image from its corners.

Color Line

The Color Line Control lets you specify the gradient color sequence. The color at the left end of the color line is the starting color of the gradient; the color at the right end is the ending color.

Cycle

This control lets you generate multiple cycles of the gradient color in equally spaced bands or rings.

Antialias

Without antialiasing, if the color sequence you specify with the Color Line Control has abrupt transitions, then the corresponding color boundaries may appear jagged in the output image. Increasing the antialias setting will eliminate these rough edges, but will take more computation time. If the gradient color transitions are all smooth, antialiasing is unnecessary.

Rainbow Gradients


Transformation Blur

Using Transformations

This command creates a blurred version of the current image. Images are blurred by replacing each pixel with a weighted average of its neighbors. The larger the neighborhood that is used, the greater the blurring effect.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the blur transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Method

This Popup List Control lets you choose the blurring method.

Blur is the fastest method and works by averaging each pixel with its four nearest neighbors.

Blur More is the next fastest method and works by averaging each pixel with its eight nearest neighbors.

Gaussian Blur is the slowest method. It works by computing a weighted average of a neighborhood whose size you can specify (see Radius below). Nearby pixels are weighted more heavily than distant pixels. This effect is a close approximation to the optical blurring that occurs when an image is out of focus.

3X3 Median and 5X5 Median The median blur method replaces each pixel with the median value of all the pixels in its neighborhood. (the median of a group of numbers is the value such that half the numbers are above and half below. The 3X3 median uses a 3 by 3 pixel neighborhood centered on the pixel; the 5X5 median uses a 5 by 5 pixel cell. The larger the cell, the stronger the effect. Median filters are effective at removing isolated pixels that are much brighter or darker than their neighbors. This kind of despeckling transformation is often helpful in reducing the graininess of an image.

Radius

The radius slider is only activated when the method is set to Gaussian. The larger the radius, the more blurred the result.

Threshold

The threshold slider is only activated when the method is set to Gaussian. Picture Window uses the threshold setting as follows:

First, the blurred image is computed. Next, pixel by pixel, the blurred image is compared to the input image. If the difference is less than the threshold, the blurred image replaces the input image; otherwise the original input image pixel is retained.

The effect of the threshold is to restrict blurring to those areas of the input image that are already relatively soft and to leave pixels that differ sharply from others around them alone. This can be very helpful, for example, in smoothing out film grain in a clear sky while leaving the adjacent tree line unblurred. A threshold setting of 255 enables full blurring; relatively small values (say in the range of 3-15) are good for selective blurring.


Transformation Sharpen

Using Transformations

This command creates a sharpened version of the current image. Images are sharpened by exaggerating the difference between each pixel's value and the average of its neighbors. This technique makes edges more distinct and gives the appearance of greater sharpness.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the sharpen transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Method

This Popup List Control lets you select the sharpening method.

Sharpen works by exaggerating the difference between each pixel and the average of four nearest neighbors.

Heavy Sharpen works by heavily exaggerating the difference between each pixel and the average of eight nearest neighbors.

When you select Unsharp Mask, radius and threshold sliders appear. Unsharp masking works by exaggerating the difference between each pixel an image created by applying a Gaussian blur of.the specified radius. This method is useful when sharpening images that are heavily blurred.

Radius

For more heavily blurred images, you may want to use a larger radius.

Threshold

To avoid exaggerating minor irregularities in relatively smooth parts of the input image while still sharpening regions that have more pronounced detail, you can increase the threshold setting. When sharpening an image by unsharp masking, the input image is first compared to a Gaussian blurred version of the input image. If the absolute value of the difference is less than the threshold, no sharpening is done. Thus a threshold of zero causes the entire image to be sharpened (with the possible exception of regions partially or totally excluded by a mask). Large threshold values cause the sharpening to be applied only to very strong and sharp edges.

Note: In addition to making the edges of objects more distinct, sharpening also exaggerates film grain, minor image defects and irregularities, and texture. For this reason, you may want to use a mask or using Unsharp Masking with a threshold (see above) to avoid sharpening skies or other image elements whose smooth texture you want to retain.


Transformation Text

Using Transformations

This command creates a version of the input image with a text overlay and optionally a solid background rectangle. You can control the size, location, text color, background color, and font of the text. To place text in the margin of an image, first use the Add Border transformation to create a border area around the image.

Positioning the text

You position the text over the input image by moving an alignment point displayed as an overlay on the input image. A rectangle is also displayed which indicates the size of the text string.

Only that part of the text that overlaps the background rectangle will be painted, any part of the text that falls outside the background rectangle is truncated. For this reason, if you are using a transparent background, it is best to leave the background rectangle covering the entire input image.

Positioning the background rectangle

You position the background rectangle over the input image by clicking and dragging its corners, sides, or interior. If an opaque background is selected (see below), then this background rectangle will be filled with the background color (see below).

Only that part of the text that overlaps the background rectangle will be painted, any part of the text that falls outside the background rectangle is truncated. For this reason, if you are using a transparent background, it is best to leave the background rectangle covering the entire input image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Font

The control lets you select the font you wish to use for the text from a list of all the TrueType and Postscript fonts installed on your system.

Font Size and Style

These controls let you select the size of the text by specifying the line height in pixels and the two-button toolbar just to the right of the Font Size control lets you select normal, bold, italic, or bold-italic type.

Line Spacing

This control lets you specify the amount of spacing between successive lines of text (assuming you enter more than one line). The line spacing can be adjusted in increments of 1/8 line from 0.5 (half spacing) to 2.0 (double spacing).

Text

You enter the text to be painted over the image here. The edit control will scroll as necessary to accomodate up to 256 lines of text.

To transfer large amounts of text from a document or other program, you can copy the text onto the clipboard and then paste it into the Text control. To paste into an edit control, simply click on the control to make the cursor a caret (vertical line) and then press Ctrl-V.

To enter special characters such as the copyright symbol into the edit control you can use the following procedure:

1) Bring up Character Map application that comes with Windows.

2) Double click on the symbol you want to insert and then click the Copy button. This copies the symbol to the clipboard.

3) Go to Picture Window's text control and position the caret where you want to insert the symbol and type Ctrl-V (the shortcut for Paste).

If you prefer, instead of using the Character Map application you can use a word processor such as Microsoft Word to insert the desired symbols into a blank document and then copy them from there to the clipboard.

Note: If you select characters from the Symbol or WingDings fonts or any other font that does not use the standard alphabet, then you must select the same font in the Font control. The characters in the Text control are always displayed using the Arial font, so special characters may not display correctly within the control but will be OK when applied to the image. For this reason, it is usually more convenient to copy the copyright, trademark, registered, and other symbols from the Arial font than from the Symbol font.

Text Color

This Color Control lets you select the text color.

Transparent Background

Use this control to make the text background either transparent or opaque. If you choose an opaque background, use the Background Color contorl (see below) to set the color of the background rectangle.

Background Color

This Color Control lets you select the color of the background rectangle. This setting is ignored if the background is set to be transparent (see above).

Alignment

This Popup List Control lets you choose how the text is aligned. When you choose Center, Left, Right, Top, Bottom, Upper Left, Upper Right, Lower Left, or Lower Right, the corresponding part of the rectangle containing the text is aligned with the alignment point you position over the input image (see above).

Tips:

To create a mask for the input image that just contains text, leave the background rectangle covering the entire input image, make the background opaque, and leave the text color black and the background color white. Then proceed to enter your text, select fonts, position the text over the image, etc. Finally, when you click OK, an image will be created that contains only the black text over a white background. You can then use this image as a mask to create various special effects based on the text you have entered.

To create blocks of text with different fonts, colors, or alignments, you must use the text transformation once for each block. As an aid to aligning the different blocks of text, it is often useful to display a grid over the input image (see Window Grid ).

You may also find the Line and Arrow tool useful when using text to annotate a specific feature in an image.


Readout Tool

Activating the readout tool pops up the readout window. This window is updated whenever you click on an image window and move the cursor with the mouse button held down. The readout window displays a small patch of the image color at the cursor against both black and white backgrounds, the location of the cursor with respect to the upper left corner of the image, and the color of the pixel at the cursor location using the color space of your choice.

Probe Size.

This setting determines the size of the area around the cursor location that is sampled to produce a color readout. If you select 1x1, then the color of the pixel at the cursor is displayed. Selecting a larger size causes the pixels in the neighborhood of the cursor to be averaged together to produce the readout. This can be useful in getting an average reading from a part of the image that is uneven.

To terminate the readout tool, close the readout window.


Zoom Tool

When you activate the zoom tool, clicking on an image window zooms that window in, centered on where you clicked. Shift-clicking zooms the image out. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other.)

To terminate the zoom tool, simply select some other tool or reselect the zoom tool from the Tools Menu or the Tool Bar.


Magnifier Tool

Activating the magnifier tool pops up the magnifier window. This window is updated whenever you click on an image window and move the cursor with the mouse button. The magnifier window displays a magnified portion of the image centered on the cursor location.

Magnification Factor

The magnifier tool supports magnification factors from 1/6X to 6X. These are absolute magnifications, not relative to the zoom factor of the image window. Large magnifications are good for examining image details. Magnifications factors less than 1X reduce the image. This lets use use the magnifier tool to display an overview of the entire image while retouching details with the image zoomed in. The magnifier window is automatically updated as you paint or clone each stroke.

You can resize the magnifier window to see as much or as little of the image at a time as you need.

To terminate the magnifier tool, close the magnifier window.


Clone Tool

Cloning is the process of painting parts of one image over another (or itself). You can use cloning to retouch dust specks and scratches, to remove image defects or unwanted background elements, to replicate parts of an image, or to copy part of one image to another.

For best results, cloning should be performed with the image zoomed in to a magnification of 1:1. If you want, you can use the magnifier tool to create an overview of the entire image while you are cloning details. Just set the magnifier to reduce the image.

Clone Window

Activating the clone tool pops up a window containing the cloning controls. These controls let you vary the cloning radius, transparency, softness, and other characteristics.

Setting the Reference Point

Before you start cloning, you must Shift-Click on an image to define the starting reference point from which image data will be copied. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other). The reference point is displayed on the screen as a circle whose radius is equal to the radius you set using the Radius slider (see below). This gives you a visual clue as to how large a patch of the image will be copied as you perform your cloning operations. You can reset the radius (and the other clone settings) at any time.

Cloning

Once the reference point is set, you are ready to start cloning. First, move the cursor to the location you want to paint over. This can be either in the same image as the reference point or in a different image entirely. Next, depress and hold down the left mouse button and slowly move the crosshair over the image. As you move the cursor while holding the mouse button down, the reference point moves by the same amount, and additional data is copied until you release the mouse button.

To reset the reference point, Shift-Click again on the same or a different image.

Radius

The radius slider lets you control the radius of the cloning brush in pixels. The smaller the brush, the finer the detail you can clone; larger brushes are good for filling large areas quickly.

Transparency

This slider lets you control the transparency of the cloning brush. The more transparent the brush, the more subtle the effect.

Softness

This slider lets you control how soft the edges of the cloning brush are. The softer the brush, the more smoothly the effects of cloning are blended with the original image.

Spacing

This slider lets you control at what spacing interval the clone tool is applied as you move the cursor. The smaller the spacing, the more the cloning applications overlap (but the more memory is required by the undo buffer).

Brush Display

A small square at the lower left of the cloning dialog displays a representation of the current cloning brush that reflects its radius, transparency, and softness settings.

Options

Clicking the [image] button lets you select various cloning options:

Copy/Lighten Only/Darken Only

These settings control how the cloning operation is performed. Lighten Only only clones those parts of the reference image that are lighter than the current image. Darken Only only copies the darker parts.

Linked/Free/One to One/Fixed

These settings control how the reference point is related to the cursor location.

Linked means the offset between the two points remains fixed when you release the mouse button. This lets you clone large areas roughly with a large brush radius and then go back with a small brush to finish up the edges without worrying about misalignment.

Free means the reference point snaps back to its original location as soon as you release the mouse button. This is useful when you want to clone multiple copies of the same object.

One to One means that the reference point is locked to the cursor location. While this is useless when cloning within a single image, it is extremely useful when cloning from one version of an image to another version of the same image, since it eliminates any possible misalignment. For example, you can use any transformation to alter an image and then selectively clone back part of the original image.

Fixed means that the reference point remains motionless once you set it even when you move the cursor. This is like using one particular spot of an image as a brush.

Continuous/Single

If you select Single, then the cloning operation is only performed when you click on an image and is not repeated as you move the cursor with the mouse button depressed.

Tiled

If you select Tiled, then the image you are cloning from is automatically repeated horizontally and vertically. Thus when you run off one side of the reference image, the reference point wraps around to the opposite side. This feature can be used to clone a repeating texture from one image onto another image.

To terminate the clone tool, simply close the clone window.

Cloning Tips


Paint Tool

The paint tool lets you paint freehand over an image using a brush with adjustable radius, transparency, softness, and color.

For best results, painting should be performed with the image zoomed in to a magnification of 1:1. If you want, you can use the magnifier tool to create an overview of the entire image while you are painting details. Just set the magnifier to reduce the image.

You cannot paint in color over a binary or black and white image without first converting it to a color image. You can accomplish this conversion by running the image through the Convert Transformation. You can paint in shades of gray on a black and white image without converting it to a color image.

Activating the paint tool pops up a window containing painting controls. These controls let you vary the brush radius, transparency, softness, color, and other characteristics.

Radius

This slider lets you control the brush radius in pixels. The smaller the brush, the finer the details you can paint; larger brushes are good for covering large areas quickly.

Transparency

This slider lets you control the transparency of the paint. The more transparent the brush, the more subtle the effect.

Softness

This slider lets you control how soft the edges of the brush are. The softer the brush, the more smoothly the effects of painting are blended with the original image.

Spacing

This slider lets you control at what spacing interval the paint tool is applied as you move the cursor. The smaller the spacing, the more the paint applications overlap (but the more memory is required by the undo buffer).

Fadeout

This slider lets you control how the brush stroke fades out (becomes increasingly transparent) as you move the cursor. The smaller the value, the less the paint applications fade.

Color

This Color Control lets you select the paint color. To choose a paint color right off the screen from an image, just shift-click on the spot whose color you want to select. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other)

Brush Display

A small square at the bottom of the cloning dialog displays a representation of the current brush that reflects its radius, transparency, and softness settings.

Options

Clicking the options button lets you select various painting options:

Copy/Lighten Only/Darken Only

These settings control how the painting operation is performed. Lighten Only only paints where the brush color is lighter than the current image. Darken Only only paints where the brush is darker.

HSV Hue Only/HSV Hue and Saturation Only/HSL Hue Only/HSL Hue and Saturation Only

These setting let you restrict painting to the hue or hue and saturation channels of the image. This lets you change the color of a region without altering its brightness. This is especially useful for colorizing a black and white image. As mentioned above, black and white images must be converted to color before you can paint on them in color.

Continuous/Single

If you select Single, then the painting operation is only performed when you click on an image and is not repeated as you move the cursor with the mouse button depressed.

1X1, 3X3, 5X5, 7X7, 9X9 Color Probe

You can use these options to set the size of the area sampled when you shift-click on an image to set the paint color.

To terminate the paint tool, simply close the paint window.


Line and Arrow Tool

The line and arrow tool lets you draw lines (optionally with arrowheads at one or both ends) over an image. The width, color, and transparency of the lines are controllable and there are several arrowhead styles avaialable as well. The lines and arrowheads are antialiased to avoid jagged edges.

For best results, drawing lines should be performed with the image zoomed in to a magnification of 1:1. If you want, you can use the magnifier tool to create an overview of the entire image while you are painting details. Just set the magnifier to reduce the image.

You cannot draw in color over a binary or black and white image without first converting it to a color image. You can accomplish this conversion by running the image through the Convert Transformation. You can paint in shades of gray on a black and white image without converting it to a color image.

Activating the line and arrow tool pops up the Line & Arrow Tool dialog box with controls that let you vary the line width, transparency, color, and arrowhead placement and style.

Width

This slider lets you control the line width in pixels. The smaller the width, the finer the line.

Transparency

This slider lets you control the transparency of the line. The more transparent the brush, the more subtle the effect.

Color

This Color Control lets you select the line color. To choose a color right off the screen from an image, just shift-click on the spot whose color you want to select. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other)

Arrow Head

This control lets you select whether you want arrowheads at the beginning of the line, the end of the line, neither, or both.

Arrow Style

This control lets you select Blunt, Medium, or Narrow arrowheads.

To use the line and arrow tool, simply position the cursor to the point where you want the line to start, press and hold down the left mouse button and move the cursor to where you want the line to end. When you release the mouse button the arrow is draw (after a short delay). If you don't like the result, simply use the Undo command to erase the line and try again.

To terminate the line and arrow tool, simply close the dialog box.


Miscellaneous Tools

The miscellaneous tools provide you with a powerful set of freehand retouching options including lightening, darkening, increasing or decreasing saturation, blurring, sharpening, and speck removal. These effects are applied using a brush with adjustable radius, transparency, and softness.

Activating the miscellaneous tools pops up a window containing various controls. These controls let you select the operation to perform and vary the brush radius, transparency, softness, and other characteristics.

Using these freehand tools effectively takes some practice. For best results, use a large, soft brush, make very small changes (set the Transparency to a high value), and move the brush slowly and evenly over the entire area you want to adjust.

Operation

This control lets you choose the effect you wish to apply to the image. The options are as follows:

Lighten/Darken

Selecting one of these options lets you lighten or darken selected parts of a black and white or color image freehand. The effect is similar to dodging and burning in a darkroom. There are a number of other techniques for lightening or darkening images that give you much more precise control.

Increase/Decrease Saturation

Selecting one of these options lets you increase or decrease the saturation of selected parts of a color image freehand.

Blur/Sharpen

Selecting one of these options lets you blur or sharpen selected parts of a black and white or color image freehand.

Speck Removal

The speck removal tool lets you click on a dust speck or other localized imperfection in an image and erase it by interpolating inward from its neighboring pixels. To use this tool, first set the radius just large enough to surround the speck, then position the cursor over the speck and click the left button once.

Like the other tools, the speck removal tool continues to operate as you move the cursor over the image with the left mouse button depressed. Used in this manner, the speck removal tool can be used to retouch elongated image defects or scratches.

The speck removal tool works best with a low transparency settings.

Smudge

This tool lets you smudge an image to create an effect like running your finger over a charcoal drawing. The image is both blurred and shifted in the direction in which you move the cursor. For the smoothest results, set the Spacing to a low value such as 0% - 10%.

Red Eye Removal

This tool lets you fix red eye, an annoying red reflection from the back of the eye that often occurs when you use an on-camera flash to shoot portraits and the subject is looking directly at the camera. Red eye manifests itself as a red disk in the pupil of the eye; to eliminate it, the red eye removal tool lets you paint a dark disk that contains a central highlight over the red reflection. When you select the Red Eye Removal tool, the transparency, softness, and spacing sliders are replaced by two color controls which let you set the pupil and highlight colors used to replace the red eye. This lets you obtain natural results regardless of the tonality and color balance of the image.

To use the red eye tool, first zoom in on the eye and then adjust the radius slider until the circle just covers the red disk. Then position the circle precisely over the red disk and click the left mouse button once. If you make a mistake, just undo it and try again. Adjust the pupil and hilight colors as necessary to obtain natural-looking results.

Add Noise

This tool lets you add random noise to parts of an image, creating an effect similar to film grain. This tool usually works best at relatively high transparency settings.

Radius

This slider lets you control the brush radius in pixels. The smaller the brush, the finer the details you can alter; larger brushes are good for working on large areas quickly.

Transparency

This slider lets you control how strong the effect will be. Values near zero have the strongest effect; values near 100% are the most subtle. For more controlled effects, it is often easiest to use a high transparency and make multiple passes over the area to build up the effects gradually.

Softness

This slider lets you control how soft the edges of the brush are. The softer the brush, the more smoothly the effects are blended with the original image.

Spacing

This slider lets you control at what spacing interval the various tools is applied as you move the cursor. The smaller the spacing, the more the individual brush patches overlap (but the more memory is required by the undo buffer).

Brush Display

A small square at the bottom of the dialog displays a representation of the current brush that reflects its radius, transparency, and softness settings. The brush may be difficult to see when you select transparency values near 100%..

Options

Clicking the options button lets you select various lightening and darkening options:

Midtones/Highlights/Shadows/All

These options are available only when the Lighten or Darken operation is selected (see above). Depending on the option you select, the corresponding parts of the image are most strongly affected. For example, to lighten the highlights of a region, first select the Lighten operation and then select the Highlights option; then use the tool over the area you wish to retouch.

Copy/Lighten/Darken

These options are available only when the Speck Removal tool is selected (see above). If you select Copy, then the speck removal tool works normally. Selecting Lighten (or Darken) replaces only pixels where the result of applying the tool is lighter than (or darker than) the underlying image.

Continuous/Single

If you select Single, then the selected operation is only performed when you click on an image and is not repeated as you move the cursor with the mouse button depressed.

To terminate the miscellaneous tools, simply close the miscellaneous tools window.


Transformation Geometry Copy

Using Transformations

This command creates an exact copy of an input image in a new window.

The copy command executes immediately without a displaying a dialog. The new window is not linked to the input image, so changes in one window do not affect the other.


Transformation Geometry Mirror/Rotate

Using Transformations

This command lets you mirror and/or rotate an image by increments of 90 degrees and place the result in a new window.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Orientation

The body of the Mirror/Rotate dialog contains eight small images showing the result of the eight possible combinations of mirroring and 90 degree rotation. Click on the one you want and then click OK or, as a short cut, double-click on the one you want.


Transformation Geometry Add Border

Using Transformations

This command lets you add a solid color border around an image. You can set the four top, bottom, left, and right border widths and the border color.

Positioning the border

The outline of the border rectangle is displayed as an overlay on the input image. You can set the border margins by dragging the four sides, the four corners, or the interior of the rectangle. You may need to increase the size of the input image window to make room to drag the border rectangle outside the image. You can also enter border margins as numbers (see below).

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Background Color

This Color Control lets you set the border color.

Border Widths

You can set the four border widths by entering them as numbers, or graphically by dragging the four corners or sides of the border rectangle (see above).

Units

This Popup Menu lets you select the units that the border widths read in.


Transformation Geometry Crop

Using Transformations

This command lets you crop an image, discarding that part of the image that lies outside of a cropping rectangle. The cropped image is displayed in a new window.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Cropping Rectangle

You select the cropping rectangle by dragging the four corners, the four sides, or the interior of the crop box displayed over the input image. The width, height, and margins of the resulting image are updated in the crop dialog as you adjust the cropping rectangle.

For greater precision in setting the cropping rectangle, remember you can zoom the input image window. You can also adjust the cropping rectangle very precisely using the up/down buttons next to the margin readouts (see below).

Size

The width and height readouts display the width and height of the output image in the current units.

Proportions

This Popup List Control lets you specify how the proportions of the cropping rectangle are constrained.

If you select Arbitrary, then you can adjust the cropping rectangle (by clicking and dragging or by entering exact margin values) to any proportions you wish.

If you select Custom, then you can enter values for the width to height ratio into the Width/Height controls (see below). Once you enter these values, the proportions of the cropping rectangle will be locked to this ratio. For example, if you increase or decrease the width of the cropping rectangle, its height will automatically be adjusted to maintain the proportions of the rectangle as close as possible to the specified ratio.

If you select one of the standard proportions, the width and height are set accordingly and the proportions of the cropping rectangle are locked to the specified ratio. To specify a vertical orientation for the cropping rectangle, select Portrait; to specify a horizontal orientation, select Landscape.

Width/Height

The width and height readouts display the ratio of the width of the output image to its height.

Margins

The margin readouts display the width of the left, right, top, and bottom margins around the cropping rectangle in the current units. To the right of each readout is a pair of buttons you can use to make single pixel adjustments to the margin widths, giving you a fine control over the positioning of the cropping rectangle. When proportions are locked, you cannot adjust the margins directly.

Units

The units control lets you select the units used in the width, height, and margin readouts. You may select pixels, in, mm, cm, or %. Selecting.% displays width settings as a percentage of the width of the input image and height settings as a percentage of the height of the input image. Regardless of the units setting, the up/down margin adjustment buttons always increment or decrement the position of the cropping rectangle by a single pixel at a time.

Cropping to a predetermined proportion

Click on the Lock Proportions check box and enter the proportions desired proportions. This will ensure that the resulting image has the specified proportions.

Setting the crop box precisely

There are two useful techniques for making very precise adjustments to the cropping rectangle. First, you can zoom the input image in to 1:1 or higher so you can see exactly where the edges of the cropping region lie. Second, you can adjust the cropping region in one-pixel increments using the up/down arrows in the margin settings.


Transformation Geometry Resize

Using Transformations

This command lets you adjust the resolution, size, or proportions of an image.

The column of controls labeled Current lists the current settings for the input image; the New column lists output image settings.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Width, Height

These controls let you set the new image width and height in pixels, inches, mm, or cm. Depending on the Preserve setting (see below) these controls may be grayed out.

Resolution

These controls display the current and new image resolution. You can set the resolution of the new image in dots per inch, mm, or cm. Depending on the Preserve setting (see below) this control may be grayed out.

File Size

These controls display the current and new file size in bytes.

Proportions

These controls display the current and new width to height ratio.

Preserve

This Popup List Control lets you choose what constraints you wish to place on the resize operation, if any. The possible settings are:

Proportions

This setting forces the width to height ratio of the new image to match that of the input image as closely as possible. If you change the Width setting, Picture Window automatically updates the Height setting and vice versa.

File Size and Proportions

This setting not only maintains the width to height ratio but also the total file size in bytes. This means that you can only change the Resolution setting which alters the physical size of the image without changing the number of pixels.

Image Size and Proportions

This setting not only maintains the width to height ratio but also the physical dimensions of the input image. This means if you change the Width setting, Picture Window automatically updates the Height and Resolution; if you change the Height setting, Picture Window automatically updates the Width and Resolution.

None

This setting lets you adjust Width, Height, and Resolution independently. Using this setting you can enlarge or reduce the image more in one direction that the other.

Interpolation Method

This Popup List Control lets you choose what type of interpolation to perform when resizing the image. The possible settings are:

Smooth

This is the default setting and produces very high quality results. When enlarging the input image, new pixels are computed by interpolating bewteen the existing pixels using techniques carefully optimized to preserve image sharpness. When reducing the input image size, each new pixel is computed by taking a weighted average of the corresponding pixels in the input image. This method is recommended for most images.

Nearest Neighbor

This setting selects the simplest method of resampling, call nearest neighbor. The color of each pixel in the output image is the color of the nearest pixel in the input image. This interpolation method is extremely fast, but when making an image larger, the individual pixels become visible as little blocks of solid color and when making an image smaller the effect can be coarse and jagged.

An interesting effect can be obtained by resizing an image smaller using Smooth interpolation and then larger again using Nearest Neighbor. This converts the image to a sort of mosaic made up of large blocky pixels.


Transformation Geometry Warp

Using Transformations

This command lets you rotate, crop, perspective correct, stretch, and warp an image. It works by stretching the four corners of a warp region in the input image out to the four corners of the result image, distorting the interior of the image as necessary.

This transformation may slightly reduce the sharpness of the input image. To compensate for this effect, use the Sharpen Transformation on the output image.

Positioning the Warp Region

The warp region is displayed as an overlay on the input image; you position the warp region by dragging its corners, sides, or interior. The interior of the warp region is filled with a reference grid which is particularly useful for perspective correction. Lines in the input image that parallel horizontal or vertical grid lines in the input image will become perfectly horizontal or vertical in the output image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Proportions

This slider lets you adjust the proportions of the the output image. This proportion is initially set to the proportions of the entire input image. Altering this setting lets you make the output image taller and narrower or shorter and wider. Any changes you make are reflected in the width and height readouts (see below).

When you apply perspective correction to an image, it is often necessary to adjust its proportions to obtain a natural appearance.

Scale Factor

This slider lets you adjust the ratio of the area of the output image to the area of the warp region. It is initially set to 1:1. Altering this setting lets you set the size of the output image. Any changes you make are reflected in the width and height readouts (see below).

Width, Height, and Resolution

These settings display and let you enter the dimensions and resolution of the output image.

Grid Divisions

This control lets you make the grid overlay on the input image finer or coarser.

Options

Reset, sets the warp region to the entire input image.

Rigid/Free

Rigid causes the warp region to scale and rotate about its center as you move any of its four corners. Use this option to rotate or scale part of the input image while preserving its proportions. When this setting is in effect, dragging a side of the warp region is disabled.

Free lets you adjust the four corners of the warp region independently. Use this option to skew, perspective correct, or warp part of the input image.

Bilinear/Perspective

Bilinear warping is faster than a true perspective warp and, for small amount of perspective correction produces nearly identical results. Bilinear warping is identical to perspective warping when you are only cropping, rotating, scaling, or shearing images.

Perspective warping is slower than bilinear warping but more accurate, especially when making large perspective corrections. A true perspective warp keeps straight lines in the input image as straight lines in the output image, regardless of their orientation. A bilinear warp only preserves straight lines that are parallel to the grid lines.

Rotating an Image

To rotate and image without stretching or distorting it, select Rigid from the options menu. This will restrict the warp transformation to just scaling, rotating, and cropping. A useful technique for correcting for camera tilt is to align the grid with the horizon. Adjusting the number of grid divisions can make this easier in some cases.

Perspective Correction

To correct the perspective of an image, select Perspective from the options menu. Then position the four corners of the grid so that the grid lines are parallel to the horizontal and verticals of the building or other object you want to correct. Adjusting the number of grid divisions can make this easier in some cases. You will probably need to adjust the proportions of the output image as well to make it look natural.

Blur before Reducing an Image

When you use the warp transformation to decrease the file size of an image, it may introduce artifacts such as moire patterns, especially if the input image contains any kind of repeating pattern. To avoid this problem, use the Blur Transformation on the input image before warping it.

Sharpen after Enlarging an Image

When you use the warp transformation to increase the file size of an image, it may reduce its sharpness slightly. To compensate for this effect, use the Sharpen Transformation on the output image.


Transformation Geometry Displace

The Displace transformation lets you distort an image in many different ways. The most interesting effects are obtained when the distortion is controlled by one or two black and white images.

There are two methods of distortion currently supported: Rectangular and Circular. If you choose Rectangular, then each pixel in the output image is derived by sampling the input image at a location displaced from the output pixel by horizontal and vertical offsets. If you select Circular, then the offsets are applied as magnifications and rotations rather than horizontal and vertical shifts. The magnitude of the offsets is determined by the Amount slider and the Horizontal and Vertical (or Magnification and Rotation) sliders.

Input Image.  The input image control displays a thumbnail of the input image for reference purposes.

Amount.  The amount control lets you control how much distortion is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image. The Amount you select acts like a scale factor which is applied to the offsets specified by the other two sliders.

Method.  The method setting can be set to Rectangular or Circular.

Rectangular. If you select Rectangular displacement, then the distortion will be based on shifting the input image horizontally and/or vertically. In this case the two sliders at the bottom of the dialog box will be labeled Horizontal Shift and Vertical Shift.

Circular. If you select Circular displacement, the distortion will be based on rotations or magnifications and/or the input image with respect to its center. In this case the two sliders at the bottom of the dialog box will be labeled Magnification and Rotation.

If you specify constant amounts for the offsets, the image is simply shifted (or rotated and magnified). However, by selecting masks into any of these controls, the displacements can be made to vary from one part of the image to another, thus creating distortion effects.

The Texture and Gradient transformations are particularly useful in creating displacement masks.


Transformation Gray Levels and Color

Using Transformations

This versatile command lets you adjust the saturation, color balance, dynamic range and midtone brightness of an image. Since brightness, contrast, color balance, and saturation interact with each other in ways that are difficult to previsualize, it can be very useful to adjust all these variables at once.

For more precise control over the brightness and contrast, see the Brightness Curve Transformation.

For more precise control over color balance, see the Color Balance Transformation.

For more precise control over saturation, see the Color Curves transformation.

The Levels and Color Transformation starts out by analyzing the input image to determine the dynamic range of the input image, i.e. its darkest and lightest points.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the Levels and Color transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Brightness

Adjusting this slider lightens or darkens the midtones of the image without affecting its shadows or highlights. You can control the brightness levels of the shadows and highlights independently using the Dynamic Range control (see below).

Color Space

If the input image is color then this control lets you select whether you want to work in the HSV or the HSL color space. When you lighten an image using HSL, it becomes whiter and may appear washed out. When you lighten an image using HSV, it retains the relative proportions of its RGB color components.

If the input image is black and white, then the Color Space control is not displayed.

Dynamic Range

Adjusting this control alters the highlight brightness and shadow darkness of the input image. The original light and dark points in the input image are marked with small vertical marks under the slider. You change the highlight brightness of the image by dragging the white slider and you change the shadow darkness by dragging the black slider. Moving the black and white sliders toward each other reduces image contrast; moving them apart increases it.

Setting the black (shadow) slider to 0% forces the darkest parts of the input image to be pure black while still preserving shadow detail. If you move the black slider beyond this point to the left into negative values, the result image will continue to become darker by making more and more of the shadow areas black as well. The effect is often more dramatic at the expense of shadow detail.

Setting the white (highlight) slider to 100% forces the lightest parts of the input image to be as bright as possible while still preserving highlight detail. The effect depends considerably on the color space you have selected (see above). If you move the white slider beyond this point to the right to values greater than 100%, the result image will continue to become lighter by setting more and more of the highlight areas to maximum brightness as well. This creates an effect of intense brightness at the expense of highlight detail.

Saturation

Adjusting this control alters the saturation of the image. Moving the slider to the right increases the saturation; moving the slider to the left decreases the saturation. Moving the saturation slider all the way to the left yields a black and white image. Moving it all the way to the right produces an image with unnaturally intense colors. Placing the slider in the middle leaves the saturation of the input image unchanged. The saturation control is not displayed if the input image is black and white.

Color Balance

This control alters the color balance of the image by applying a color filter to it. You can set the color balance in two ways: by clicking on the input image window or by selecting a color using the color picker.

Clicking on the input image window samples the color of the input image at the point you click and sets the color balance to the complement of that color. This has the effect of neutralizing in the result image the color you select in the input image. Thus, if you can find a spot in the input image that should be a neutral gray, clicking on it will automatically compute the correct color filter to apply to the image to achieve this effect.

If you prefer, you can click on the small square that makes up the Color Balance color control to bring up a color picker . You can use this control to specify a filter color directly from the color wheel or the filter bank.

If the input image is black and white, you can use the color balance control to tint it. For a much more powerful way to tint black and white images, see the Tint Transformation .

Options

The [image] button pops up an option menu consisting of the following items:

Reset returns all of the settings to their initial default values.

Full Range causes the dynamic range control to be set so that the black point is at 0% and the white point at 100%. This makes full use of the available dynamic range without losing highlight or shadow detail.

Probe Size (1x1/3x3/5x5/7x7/9x9)

These options let you control the sample size used by the color balance probe. Larger probe sizes are useful for obtaining an average reading of any area of the image that does not have a smooth texture; smaller probe sizes let you get precise readings of very small areas. The currently selected probe size is shown with a check mark.


Transformation Gray Negative

Using Transformations

This command creates a new image which is the negative of an input image. It is useful for inverting mask images or for creating special effects.

The negative command executes immediately without a displaying a dialog. If the input image is color, then the output image is computed by taking the negative of each of its RGB components. This differs from a color reversal film negative which has an orange masking layer.

You can also achieve this effect and many others using the Brightness Curve transformation.


Transformation Gray Brightness Curve

Using Transformations

This command lets you adjust the brightness curve of an image. The brightness curve controls the gray scale of the image; by adjusting its curve you can make an image lighter or darker, stretch or compress any part of the tone scale, or create special effects like solarization and posterization.

The brightness curve dialog is resizable; the larger you make it, the larger its curve control (see below) gets. The brightness curve dialog has the following controls:

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the brightness curve transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Color Space

If the input image is color then this control lets you select whether you want to work in the HSV or the HSL color space. When you lighten an image using HSL, it becomes whiter and may appear washed out. When you lighten an image using HSV, it retains the relative proportions of its RGB color components. When you modify an image using RGB, each channel is affected independently.

Curve

The Curve Control occupies the entire bottom part of the brightness curve dialog.

Curve Examples


Transformation Gray Brightness

Using Transformations

This command lets you adjust the overall brightness of an image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much and in which direction the brightness of the image is changed. Positive values make the image brighter; negative values make the image darker. You can apply the transformation to the entire image, making it brighter or darker, or you can specify an amount mask to brighten or darken different parts of the input image by different amounts. When you use an amount mask, the input image is left unchanged where the mask image is a midlevel gray; it is brightened where the mask is brighter and darkened where the mask is darker. You can control the degree of brightening and darkening caused by the mask image using the double slider.

Color Space

If the input image is color then this control lets you select whether you want to work in the HSV or the HSL color space. When you lighten an image using HSL, it becomes whiter and may appear washed out. When you lighten an image using HSV, it retains the relative proportions of its RGB color components. When you modify an image using RGB, each channel is affected independently.

Preserve

There are many different ways to lighten or darken an image. This Popup Menu control lets you select what parts of the gray scale of the input image are most affected and what parts of the gray scale remain unchanged:

Black lightens or darkens the input image by applying a curve that keeps black black and has its strongest effect on the image highlights.

White lightens or darkens the input image by applying a curve that keeps white white and has its strongest effect on the image shadows.

Both lightens or darkens the input image by applying a curve that keeps black black and white white and has its strongest effect on the image midtones.

Neither lightens or darkens the input image by applying a curve that adds or subtracts the same amount to the entire gray scale, affecting all levels equally.


Transformation Gray Tint

Using Transformations

This command lets you convert a black and white image to a color image by changing different gray levels to different colors. The tint dialog is resizable; the wider you make it, the longer its color line control (see below) becomes. The dialog has the following controls:

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the tint transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Color Line

The Color Line Control lets you specify how different gray levels in the input image are converted to different colors. Black pixels in the input image are assigned the color at the left end of the color line; white pixels are assigned the color at the right end. Intermediate grays are assigned intermediate colors along the line.


Transformation Gray Light Falloff

Using Transformations

This command lets you correct for the tendency in photographs, especially those taken using wide angle lenses, for the corners of the image to be somewhat darker than the center due to light falloff. In order to apply this transformation to an image, you must start with a full, uncropped image of the entire frame and you must know the focal length of the lens you used to take the picture.

This transformation adjusts the brightness of the image based on the cosine of the angle from the center of the lens to each location on the film. It only works for rectilinear lenses, not for fisheye or other types of lenses that make straight lines appear curved.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Lens Focal Length

Enter the focal length of the lens in millimeters. The shorter the focal length you enter, the stronger the correction. When using 35mm film, the effect of the transformation is negligible for 50mm and longer lenses.

Film Size

Enter the longer dimension of the film size in millimeters. For example, for 35mm film the frame size is 24x36mm so you would enter 36; for 6x6cm, you would enter 60, for 6x7cm, you would enter 70. For other film formats, enter either the width or the height of the frame in mm, whichever is larger.

Method

This Popup List Control lets you select which method to use to correct for light falloff. The Lighten Corners option leaves the brightness of the center of the image unchanged and progressively lightens the image based on the distance from the center. Usually this is the best method, but in some cases, if there are bright areas in the corners of the image, some loss of highlight detail may occur. In this case, use the Darken Center option which leaves the brightness of the corners of the image unchanged and progressively darkens the image toward the center.


Transformation Gray Gamma Adjust

Using Transformations

This command lets you convert a black and white or color image from one gamma value to another. While Picture Window standardizes on a gamma value of 2.22 for displaying images on the monitor, other gamma values are commonly used by other applications.

For prepress work, a gamma value of 1.8 is normally used to more accurately represent the characteristics of printing presses. The standard Macintosh gamma value is 1.4. A gamma value of 1.0 corresponds to so-called linear gamma where the brightness of the image is proportional to the pixel values.

With the Gamma Adjust transformation, you can prepare images for export to a service bureau or printer that assumes a gamma of 1.8 or to a Macintosh that uses gamma 1.4 – or you can import images prepared assuming different gamma values and correct them for use with Picture Window.

The higher the monitor gamma, the darker the image. Images prepared assuming gamma values of 1.8 or 1.4 will look too dark and saturated when displayed on a monitor calibrated to gamma 2.22. Images prepared using a gamma 2.22 calibrated monitor will look too light and washed out when displayed on a monitor calibrated to gamma 1.8 or 1.4.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Convert from gamma

Use this control to select the gamma of the image you want to convert.

To gamma

Use this control to select the gamma you want to convert to.


Transformation Gray Combine Channels

Using Transformations

This command lets you create a color image from three black and white images of the same size.

Color Space

This Popup List Control lets you select which set of three color channels you want to combine (RGB, HSV, HSL, or CMY)

The CMY color space lets you combine three images such as black and white photos of the same subject taken through cyan, magenta, and yellow filters into a single RGB color image. The channels are combined additively as cyan, magenta, and yellow light, as opposed to the more common subtractive combination of cyan, magenta, and yellow inks.

Color Channels

These three Color or Image Controls let you assign fixed gray levels, black and white images, or 16-bit black and white images (Pro version only) to each channel. At least one of the controls must be set to an image; if more than one is set to an image, then all the images must have the same type and  dimensions in pixels.

If you assign a constant gray level to a color channel, then the channel will be set to that level over the entire output image.


Transformation Color Balance

Using Transformations

This command lets you add or remove color casts from an image. You can specify up to three separate pairs of casts: one for highlights, shadows, and midtones. Before starting, Picture Window scans the input image for highlight and shadow color casts.

The highlight cast has the most dramatic effect on the color balance of the image since bright colors are more easily distinguished than dark colors.

Removing a color cast means making colors that match a color become neutral; adding a color cast is the reverse; it makes neutrals take on a color. Removing a color cast is like passing an image through a filter whose color is the complement of the color cast; adding a color cast is like passing an image through a filter whose color is the same color as the cast. Removing and adding a color cast at the same time makes colors which match the remove cast become the color of the add cast.

For example, to remove a greenish cast from an image, select a greenish color to remove. The more saturated you make the cast to remove, the more green you take out of the image. To add a warming cast to an image to simulate early morning or late afternoon light, add a reddish to yellowish cast. Again, the more saturated the color, the stronger the effect.

The color balance transformation works by applying three curves to the input image—one for the red channel, one for green channel, and one for the blue channel. These curves are displayed on the right side of the dialog box.

Each curve is defined by three points corresponding to the current highlight, midtone, and shadow color selections. You can either set the curves by choosing color casts to add and remove, or you can drag points on the curve to select the colors.

Six color patches are displayed down the left side of the dialog box—colors to remove and add for highlights, shadows, and midtones.

The highlight color patches are displayed against a white surround; the shadow patches against a black surround, and the midtone patches against a gray surround. Clicking on any of these patches pops up a Color Picker you can use to change its color.

Options

The [image] button pops up an option menu consisting of the following items:

Reset returns all of the color balance settings to their initial values.

Full Range causes the lightest detected color in the input image to become pure white and the darkest detected color in the input image to become pure black, thus utilizing the full available dynamic range.

Load lets you restore a previously saved set of color balance settings for application to the same or to a different image.

Save As lets you save the current color balance settings in a file for later use.

Probe Size (1x1/3x3/5x5/7x7/9x9)

These options let you control the sample size used by the probe, should you choose to enable it (see below). Larger probe sizes are useful for obtaining an average reading of any area of the image that does not have a smooth texture; smaller probe sizes let you get precise readings of very small areas. The currently selected probe size is shown with a check mark.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the color balance transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Probe

This Popup List Control lets you select highlight, midtone, or shadow color casts you want to remove by pointing to parts of the input image that you want to be made neutral. Selecting none disables the probe feature. Selecting highlight, shadow, or midtone lets you click on the input image to set the highlight, shadow, or midtone cast to remove to the color of the pixel you point to. At the same time Picture Window automatically sets the corresponding cast to add to a neutral gray of the same luminance.

Highlight

This Popup List Control lets you select how the highlight cast is specified. Selecting None sets the cast to remove and the cast to add both to pure white. Selecting Auto sets the highlight cast to remove to be the one Picture Window detected automatically on startup. Selecting Custom lets you choose the highlight cast to remove with the Color Pickeror probe.

Shadow

This Popup List Control lets you select how the shadow cast is specified. Selecting None sets the cast to remove and the cast to add both to pure black. Selecting Auto sets the shadow cast to remove to be the one Picture Window detected automatically on startup. Selecting Custom lets you choose the shadow cast to remove with the Color Pickeror probe.

Midtone

This Popup List Control lets you select how the midtone cast is specified. Selecting None disables midtone cast correction. Selecting Custom lets you choose the midtone cast to remove with the Color Pickeror probe.

Color Balancing Tips


Transformation Color Curves

Using Transformations

This command lets you adjust the color curves of an image. Using color curves you can alter each of the three components that make up a color image using the HSV, HSL, or RGB color model. This lets you adjust the hue, saturation, and brightness of an image all in one operation. Or you can adjust its red, green, and blue layers independently.

Before attempting to use this transformation, you should first master the Brightness Curve transformation which it closely resembles.

The color curves dialog is resizable; the larger you make it, the larger its curve control (see below) gets. The color curve dialog has the following controls:

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the color curve transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Color Space

If the input image is color then this control lets you select whether you want to work in the RGB, HSV, or the HSL color space.

According to the color space you select, you can further select which of the three components you wish to work on. For example, if you choose the HSV color space, then you can switch among the H, S, and V components. Each component has its own curve and can be adjusted independently of the other two. When you apply the transformation to the input image, each of the three components is modified according to its own curve.

Curve

The Curve Control occupies the entire bottom part of the color curve dialog.

When you are modifying the HSV or HSL hue (H) component, remember that hue is circular since it starts and ends with the same color (red). Therefore, hue curves wrap around from the right hand to the left hand edge of the graph and from the top edge to the bottom edge of the graph.

Options

The [image] button pops up an option menu consisting of the following items:

Reset returns all of the color curve controls to their default states.

Load lets you restore a previously saved set of color curves for application to the same or to a different image.

Save As lets you save the current color curves in a file for later use.

Curve Examples


Transformation Color Saturation

Using Transformations

This command lets you adjust the overall color saturation of an image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much and in what direction the saturation of the image is changed. Positive values make the image more saturated; negative values make the image less saturated. You can apply the transformation to the entire image, making it more or less saturated, or you can specify an amount mask to saturate or desaturate different parts of the input image by different amounts. When you use an amount mask, the input image is left unchanged where the mask image is a midlevel gray; it is made more saturated where the mask is brighter and desaturated where the mask is darker. You can control the degree of saturation change caused by the mask image using the double slider.

Color Space

If the input image is color then this control lets you select whether you want to work in the HSV or HSL color space. Using HSL, saturation changes are more pronounced in the midtones; using HSV, saturation changes are more pronounced in the highlights.

Preserve

There are many different ways to saturate or desaturate an image. This Popup Menu control lets you select what parts of the saturation scale of the input image are most affected and what parts of the scale remain unchanged.

Low saturates or desaturates the input image by applying a curve that keeps unsaturated areas unsaturated and has its strongest effect on the most saturated areas.

High saturates or desaturates the input image by applying a curve that keeps saturated areas saturated and has its strongest effect on the least saturated areas.

This setting should normally be avoided, since it exaggerates color in neutral areas of the input image that contain little or no color information to begin with. By arbitrary convention the hue of a perfectly neutral gray is zero which corresponds to red. Increasing the saturation of a neutral gray region therefore makes it red.

Low and High saturates or desaturates the input image by applying a curve that keeps unsaturated areas unsaturated and fully saturated areas fully saturated and has its strongest effect on the regions of midlevel saturation.

Neither saturates or desaturates the input image by applying a curve that adds or subtracts a the same amount to the entire saturation scale, affecting all levels equally. This setting should normally be avoided (see above).


Transformation Color Extract Channel

Using Transformations

This command lets you extract one channel of a color image as a black and white image or one channel of a 48-bit color image as a 16-bit black and white image (Pro version only).

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Channel

This Popup List Control lets you select which color channel of the input image you want to extract. The choices are:

Luminance

Red, Green, Blue

HSV Hue, Saturation, Value

HSL Hue, Saturation, Lightness

Hints

A channel you extract can be used as a mask for the input image. For example, this lets you create a mask based on saturation or hue.

You can generate interesting effects by extracting the three color components of an image, modifying them, and then recombining the modified channels using the Combine Channels transformation.


Transformation Color Monochrome

Using Transformations

This command lets you convert a color image to a black and white image. This transformation is like photographing a color scene on black and white film through a colored filter. You can set a filter color (or color image) to emphasize some colors in the input image over others. As a rule of thumb, if you want a certain color to come out lighter, use a filter of the same color; if you want to make it come out darker, use a filter of the complementary color.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the monochrome transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Filter

This Color or Image Control lets you select the color of the filter used in converting from color to black and white. Selecting a color image lets you vary the filter color over different parts of the input image.

Hints

The default yellow-green color gives a result that corresponds to the luminance of the image. When you select a filter color, colors in the input image that match the filter color are rendered lighter shades of gray in the output image and color in the input image that are the complement of the filter color are made darker.

After you are done, you may want to adjust the brightness curve or levels in the image to improve its dynamic range, brightness, and contrast.


Transformation Color Correction
Transformation Color Correction (This transformation is in Picture Window Pro only)

Using Transformations

This command lets you apply pinpoint color corrections to an image that modify only certain colors and leave the rest unchanged. The ability to localize adjustments to certain colors often makes this transformation more useful than Color Balance or Filter which change all the colors in an image. For example, you can use the Color Correction transformation to adjust skin tones in a portrait without altering other colors in the clothing or background.

The Color Correction transformation is based on the hue and saturation components of the HSV color space, as represented by the color wheel. You specify a correction by placing control points on the color wheel; each control point has two parts: an input color and an output color. When the correction is applied, all pixels in the input image whose hue and saturation matches one of the input colors is changed to the corresponding output color with the same value (brightness). Colors inbetween the control points are interpolated to make smooth transitions.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the color correction transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Radius

Adjusting this slider controls how closely colors must match those of a control point to be affected by the transformation. Larger radius values affect more of the neighboring colors; smaller radius values narrow the effect to only those colors that match more closely.

Show Corrected Color Wheel

Normally, Picture Window displays a color wheel at the bottom of the dialog box (see below). When the Show Corrected Color Wheel checkbox is checked the Color Correction transformation applied to the color wheel itself and the results of this are displayed in its place. This gives you a visual representation of which colors are being changed and by how much. To return to the normal color wheel display, uncheck the check box.

Color Wheel

The color wheel and the control points displayed over it are central to this transformation. A control point has two parts – an input color and an output color. If both are the same, the control point in displayed as a circle. If the output color differs from the input color, a smaller circle is displayed at the input color, connected by an arrow pointing to the output color. All colors in the input image whose hue and saturation match the input color are changed in the output image to the output color with the same value (brightness). Colors in between control points are interpolated to make a smooth transition.

Initially, there are 7 control points set on white, red, yellow, green, cyan, blue, and magenta. Each of these control points has both its input and output colors set the same. These control points ensure that white and the fully saturated primary and secondary colors in the input image are left unchanged in the output image, which is often a good starting point if you just want to make a minor change. Applying the transformation with this initial configuration, however, will have no effect on the intput image as none of the output colors differs from its input color.

To add a new control point, shift-click (hold down either Shift key while clicking with the left mouse button) on the color wheel at the desired input color location. Or, you can add a control point by using the Probe. To do this, make sure [image] button is depressed and then click once on a color in the input image window you want to change. You can create up to 32 control points; Picture Window beeps if you try to create more than 32.

To remove a control point, control-click (hold down the either Ctrl key while clicking with the left mouse button) on it.

To change the output color of a control point, click and drag its circle on the color wheel. This will extend an arrow from the control point to the desired output color. Once an arrow has been created, you can make additional changes to the output color by dragging the arrow head.

To change the input color of a control point, first make the output color different from the input color, if necessary. Then you can change the input color by dragging the small circle at the base of the arrow.

As you move the mouse cursor over the color wheel, a readout just below the color wheel displays, for reference purposes, the hue and saturation values corresponding to the cursor location.

Options

The [image] button pops up an option menu consisting of the following items:

Reset returns all of the color correction settings to their initial values.

Load lets you restore a previously saved set of color correction settings for application to the same or to a different image.

Save As lets you save the current color correction settings in a file for later use.

Probe Size (1x1/3x3/5x5/7x7/9x9)

These options let you control the sample size used by the probe, should you choose to enable it (see below). Larger probe sizes are useful for obtaining an average reading of an area of the image that does not have a smooth texture; smaller probe sizes let you get precise readings of very small areas. The currently selected probe size is shown with a check mark.

Probe

The [image] button lets you enable or disable the probe. When the button is depressed, the probe is active; when it is not depressed, the probe is inactive. When the probe is active, clicking on any image window (not including the Preview window) samples the color at the point where you click and creates a new control point at the corresponding point in the color wheel.

Hints

To make a correction of one color in an image,.click the [image] button to activate the probe and then click on a part of the input image having the color you want to change. Next go to the color wheel and click and drag on the new control point you just created. To make the color more or less saturated, drag it toward the edge or toward the center of the color wheel. To adjust its hue, drag the control point either clockwise or counterclockwise about the center. Finally, click Preview to check the results and OK if it looks good. To make further adjustments, click again on the input image to create additional control points.

If the transformation is changing colors close to one you selected and you want these to remain unchanged, you can either reduce the Radius setting or create additional control points whose input and output colors are the same to prevent the nearby colors from being modified.

If there are several elements in the image that have the same color, and you only want to adjust some of them, you will have to create a mask to isolate the parts you want to change.


Transformation Color Registration

Using Transformations

This command lets you compensate for the slight misregistration between the red, green, and blue channels of a color image that is introduced by some color scanners. This problem shows up as color fringes at sharp edges in the image. While misregistration is rarely if ever a problem with PhotoCD scans, most inexpensive slide and flatbed scanners produce color scans that are misregistered to some degree.

The color registration transformation works by displacing the green and/or blue channels horizontally or vertically with respect to the red channel which remains fixed. You can specify the displacement offsets in half pixels as positive or negative values.

To use this transformation, first scan a test image consisting of sharply defined black on white areas. You can use crisp printed text, or you can draw sharp black horizontal and vertical lines on white paper. When you look at the scanned images, pay careful attention to the black to white transitions. If you see fringes of one color on one side of a vertical or horizontal line with the complementry color on the opposite side, then your image is misregistered.

To correct color fringes on horizontal lines, adjust the vertical offsets; to correct color fringes on vertical lines, adjust the horizontal offsets and preview until the fringes are minimized. If the color fringes are magenta/green, adjust the green offsets; if the color fringes are blue/yellow, adjust the blue offsets.

Options

The [image] button pops up an option menu consisting of the following items:

Reset returns all of the color registration offsets to zero.

Load lets you restore a previously saved set of color registration settings for application to the same or to a different image.

Save As lets you save the current color registration settings in a file for later use.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Green Horizontal Offset

Green Vertical Offset

Blue Horizontal Offset

Blue Vertical Offset

These controls let you set the horizontal and vertical displacements in half pixels for the green and blue color channels.


Transformation Special Effects Emboss

Using Transformations

This command lets you create an embossed version of an image. It works by combining the input image with its negative, offset by a small distance in a given direction.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the emboss transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Color Space

This Popup List Control lets you select HSV, HSL, or RGB color space. If you select RGB, then the red, green, and blue channels of the input image are embossed separately and combined in the output image. If you select HSV or HSL, then only the V or L channel is affected, leaving the hue and saturation information unchanged.

Radius

Adjusting this slider controls the offset used to emboss the input image, in pixels. The smaller the offset, the finer the detail, but the less contrast in the result.

Method

This Popup List Control lets you select how the results of embossing are applied to the input image.

If you choose Normal, the embossed image is the result.

If you choose Shadow, the input image is lightened where the embossed image is brighter than a midlevel gray and darkened where the embossed image is darker than a midlevel gray.

Angle

The embossing angle is the direction of the offset. Varying the angle is like changing the direction of the light source that illuminates the embossed image.

Height

This slider controls the apparent height the embossed image is raised. Increasing the height increases the contrast in the result image. You can compensate for the reduced contrast produced by choosing a small radius by increasing the height.


Transformation Special Effects Edge

Using Transformations

This command lets you locate, lighten, or darken edges in an image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the edge transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Color Space

This Popup List Control lets you select HSV, HSL, or RGB color space. If you select RGB, then the red, green, and blue channels of the input image are edge enhanced separately and combined in the output image. If you select HSV or HSL, then only the V or L channel is affected, leaving the hue and saturation intact.

Method

This Popup List Control lets you select from three different edge detectors.

The Roberts edge detector produces thinner but less distinct edges than the Sobel edge detector. The Laplacian edge detector works by computing the difference between a pixel and its eight nearest neighbors.

Action

This Popup List Control lets you select how the edge information is used to modify the input image. Choosing Compute causes the result of the edge transformation to be the output image. Choosing Lighten or Darken causes edges detected in the input image to be lightened or darkened.


Transformation Special Effects Difference

Using Transformations

This command lets you subtract one image from another and display the differences.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the difference transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Subtract Image

This Color or Image Control lets you select the color or image to be subtracted from the input image.

Operation

This Popup List Control lets you select how the difference is computed.

Difference causes the subtract image to be subtracted from the input image. Everywhere the subtract color or image is brighter than the input image, the result is black.

Offset Difference generates an output image that is a midlevel gray where the input and subtract images are the same. The output image is darker where the subtract image is brighter than the input image and lighter where the subtract image is lighter than the input image.

Absolute Difference generates an output image that is black where the input and subtract images are the same. The output image increases in brightness where either image differs from the other.


Transformation Special Effects Add Noise

Using Transformations

This command adds random noise to an image creating a grainy effect.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the add noise transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Method

This Popup List Control lets you select what kind of random noise is added to the image.

Uniform random noise has the property that all noise values are equally likely.

Gaussian random noise is more likely to make small changes to the image than large ones.

Channel(s)

This Popup List Control lets you select which channels have noise added to them. This control is only displayed if the input image is in color.

RGB generates an output image where noise has been added to the red, green, and blue channels of the input image.

HSV generates an output image where noise has been added only to the HSV V channel.

HSL generates an output image where noise has been added only to the HSL L channel.


Transformation Special Effects High Contrast

Using Transformations

This command lets you create a high contrast black and white version of the input image. It works by comparing the brightness of each pixel in the input image to a threshold value. Where the pixels are brighter than the threshold, the output image is white; where they are darker, the output image is black. Output pixels that lie on the boundary between black and white areas, are set to an appropriate gray level to make the boundary appear smooth.

You can use the Tint transformation to colorize the output image if you want some color scheme other than black and white.

This transformation is similar to using the Brightness Curve transformation, except that it handles the boundary between black and white areas in the output image more accurately.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the high contrast transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Threshold

The threshold amount control lets you control what gray level the input image is tested against to decide if the output image is black or white. You can use the same threshold value for the entire image, or you can specify a mask to use different thresholds over different parts of the image.


Transformation Special Effects Tile

Using Transformations

This command lets you cover an output image with multiple copies of a rectangular region in an input image. You control the number of copies and whether they are mirrored horizontally or vertically.

Selecting the tile region

You select the rectangular tile region in the input image by dragging the corners, sides, or interior of the rectangular overlay in the input image window.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Size

This control displays the width and height of the output image in pixels based on the currently selected tile region, mirror settings, and repeat factors.

Horizontal Mirror

This Popup List Control lets you reflect the tile region about its left or right edge.

Vertical Mirror

This Popup List Control lets you reflect the tile region about its top or bottom edge.

Horizontal Repeat

This Popup List Control lets you tile the output image with multiple repeated copies of the tile region. These copies are repeated horizontally, yielding an output image that is wider than the input image.

Vertical Repeat

This Popup List Control lets you tile the output image with multiple repeated copies of the tile region. These copies are repeated vertically, yielding an output image that is taller than the input image.


Transformation Special Effects Equalize

Using Transformations

The equalize transformation computes and applies a brightness curve to the input input so that each brightness level is represented equally in the output image. In other words, it attempts to adjust the brightness levels of the input image so that its histogram becomes flat. This transformation is often useful for bringing out hidden detail in an image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the equalize transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Color Space

This control is only displayed if the input image is a color image. It lets you select which brightness component of the input image is equalized: the HSV value or the HSL lightness.


Transformation Special Effects Kaleidoscope

Using Transformations

This command generates a number of effects similar to those created by a kaleidoscope, but with many more variations. The result image is created by rotating and reflecting a sector of the input image in a pattern that has circular symmetry about the center of the result image.

When you start up the Kaleidoscope transformation, it displays an overlay over the input image window to show you the sector of the image will be repeated to fill the result image.

Two control points and two intersecting line segments are displayed over the input image. The angle between the two lines is determined by the repeat factor (see below). You can click and drag the control point at the intersection of the two lines to position the center point of the kaleidoscope. You can click and drag the other control point to rotate and scale the sector about the center. The further you move the second control point from the center point, the smaller the sector will appear in the result image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Repeat Factor

This control lets you select the number of times the image will repeat as you rotate about the center. A traditional kaleidoscope has 6-fold rotational symmetry which corresponds to a repeat factor of 6. You can set the repeat factor to any value from 2 to 1000.

Style

This Popup List Control lets you select several different types of rotational symmetry. A little experimentation will illustrate the different effects.


Transformation Special Effects Spiral

Using Transformations

This command warps a circular region of an image by twisting it into a spiral. Several different types of spirals are supported. When you start up the Spiral transformation, it displays an overlay over the input image window to show you the circular region of the image that will be twisted. A control point is displayed at the center of the circle. Clicking and dragging this point repositions the circular region. The radius of the circle is adjusted with the Radius slider in the Spiral dialog box.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Type

This Popup List Control lets you select several different types of spiral:

Linear

In a linear spiral, the twist angle increases proportionally to the radius.

Logarithmic

In a logarithmic spiral, the twist angle increases as the logarithm of the radius.

Hyperbolic

In a hyperbolic spiral, the twist ange increases as the reciprocal of the radius. Consequently, this type of spiral is very tightly wound near the center.

Solid

The option causes the entire interior of the circular region to be rotated as a unit.

Radius

The radius slider lets you select the size of the region to be twisted. As you vary the radius, the circle displayed over the input image changes size to show you what part of the input image will be affected.

Spin

The spin slider lets you select the amount of twist to be applied to the input image. The lower the value you select, the less the input image will be distorted. Negative values twist in the opposite direction.

Antialias

Certain spiral settings result in images that have slightly jagged edges. For example, when computing a solid spiral, the boundary between the rotated and unrotated portions of the image may be a little rough. Or, the center region of a hyperbolic spiral may also degrade into individual pixels. To counter this phenomenon which is called aliasing, you can increase the antialias setting. Doing so will reduce the aliasing artifacts at the expense of increased time to compute the transformation.


Transformation Special Effects Calendar

Using Transformations

This command creates a version of the input image with a text overlay that contains a calendar for one or more months and optionally a solid background rectangle. You can control the size, location, text color, background color, and font of the calendar text. To place a calendar in the margin of an image, first use the Add Border transformation to create a border area around the image.

Positioning the calendar

You position the calendar over the input image by moving an alignment point displayed as an overlay on the input image. A rectangle is also displayed which indicates the size of the calendar.

Only that part of the text that overlaps the background rectangle will be painted, any part of the text that falls outside the background rectangle is truncated. For this reason, if you are using a transparent background, it is best to leave the background rectangle covering the entire input image.

Positioning the background rectangle

You position the background rectangle over the input image by clicking and dragging its corners, sides, or interior. If an opaque background is selected (see below), then this background rectangle will be filled with the background color (see below).

Only that part of the text that overlaps the background rectangle will be painted, any part of the text that falls outside the background rectangle is truncated. For this reason, if you are using a transparent background, it is best to leave the background rectangle covering the entire input image.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Font

The control lets you select the font you wish to use for the calendar text from a list of all the TrueType and Postscript fonts installed on your system.

Font Size and Style

These controls let you select the size of the calendar text by specifying the line height in pixels and the two-button toolbar just to the right of the Font Size control lets you select normal, bold, italic, or bold-italic type.

Text Color

This Color Control lets you select the text color.

Transparent Background

Use this control to make the text background either transparent or opaque. If you choose an opaque background, use the Background Color contorl (see below) to set the color of the background rectangle.

Background Color

This Color Control lets you select the color of the background rectangle. This setting is ignored if the background is set to be transparent (see above).

Duration

This control lets you select how many months you want the calendar to run (1, 2, 3, or 12) and the month layout for calendars that cover more than one month.

Start At

These controls let you select the starting month and year for the calendar.

Tips:

To create a mask for the input image that just contains the calendar text, leave the background rectangle covering the entire input image, make the background opaque, and leave the text color black and the background color white. Then proceed to enter your text, select fonts, position the text over the image, etc. Finally, when you click OK, an image will be created that contains only the black text over a white background. You can then use this image as a mask to create various special effects based on the text you have entered.


Transformation Special Effects Stereo

Using Transformations

This command lets you prepare a pair of stereo images for viewing. The stereo transformation supports two types of viewing: using special glasses with red and cyan lenses (red on the left, cyan on the right) or using a viewer that superimposes two side by side images.

If you select the Red/Cyan method, then a single image is generated with the left image displayed in red and the right image superimposed over it in cyan. This type of image is sometimes called an anaglyph. For the Red/Cyan viewing method, both images should normally be black and white. If you select color images, they will be converted to black and white internally within the transformation in the process of computing the anaglyph.

If you select the Side by Side method, the result is an image consisting of the left and right images arranged side by side.

In either case, to get the best result it is usually necessary to adjust the horizontal and vertical offsets between the two images. It is usually easiest to do this by 1) enabling auto preview, 2) setting the method the Red/Cyan, and 3) adjusting the sliders to get the images to line up.

When previewing, the size of the preview image is locked to the size of the left image so that the transformation can be recomputed more quickly. Areas in the preview image where the left and right images do not overlap are displayed as black. When the final version of the transformation is computed, these black areas are automatically eliminated.

Left and Right Images

The left and right image controls let you select the left and right images from a matched set of stereo photographs.

Horizontal and Vertical Offsets

These sliders let you adjust the offsets between the two images to get the best stereo effect.

Method

This Popup List Control lets you select the Red/Cyan or the Side by Side viewing method.

Notes:

You can extract the individual left and right black and white images from an anaglyph with the Extract Channel transformation. To retrieve the left image, extract the red channel; for the right image, extract the blue or green channel.

Stereo pairs of images are normally created using a special stereo camera that take two pictures simultaneously. For stationary subjects, however, you can get the same effect by taking two photographs with the same camera by offsetting the lens by approximately the distance between your eyes (about 2 inches).

Stereo glasses and stereo viewers are available from a number of suppliers. For more information, see the links sections of our web site (www.dl-c.com).


Transformation Special Effects Halftone

Using Transformations

This command lets you render an image using a halftone screen. Halftoning is a technique for representing a continuous tone image using only two colors -- black and white. These black and white dots are clustered in patterns to simulate the different gray levels in the input image. There are many different halftoning techniques, a number of which are supported by Picture WIndow. In addition, the halftone transformation can use a custom screen that you supply.

Input Image

The input image control displays a thumbnail of the input image for reference purposes. If you supply a black and white input image, the result of halftoning is a binary image. If you supply a color input image, the result is a color image created by halftoning the red, green, and blue components separately and combining them into a single result; each pixel in the color result image is therefore one of eight possible colors.

Amount

The amount control lets you control how much of the halftone transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Method

This Popup List Control lets you select the halftoning method from a number of options. The best way to understand the different halftoning patterns is to experiment with this setting. In general, the halftoning patterns with the smallest sizes (e.g. 6x6) are best at representing finer details at the expense of being able to represent fewer different gray levels. The Error Diffusion method differs from the others in that it has no fixed cell size and produces a more random effect.

If you select Custom, then you can specify any grayscale image as the halftone screen using the Screen control (see below).To generate the output image, the input image is compared to the halftone screen image, a pixel at a time and if the input image pixel is darker than the screen pixel, the corresponding output pixel is set to black; otherwise it is set to white.

Halftone Screen

The halftone screen image control lets you select a black and white image for use as a custom halftone screen. This setting is ignored unless the Method control (see above) is set to Custom.

For best results, screen images should have rougly equal numbers of pixels of each possible gray level and should have a fairly fine texture. A nearly infinite variety of such screens can be generated using the Texture transformation followed by the Equalize Transformation . The halftone screen image is tiled as necessary to cover the input image and therefore can be any size.

Note: Because of their repeating bit patterns, halftones previewed at a zoom factor other than 1:1 (or higher) often look very strange and this should normally be avoided.


Transformation Special Effects Interlace

Using Transformations

This command lets you extract either the even or the odd rows of an image. This is useful when processing captured interlaced video images as the time lag between the even scan lines and the odd scan lines can create annoying artifacts if the subject is moving. The interlace transformation lets you select just the even or the odd scanlines and fills in the missing data by interpolation.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Frame

This Popup List Control lets you select which subframe of the input image you want to extract. If you select Even, then the even scanlines will pass through unchanged into the output image while the odd scanlines will be regenerated by interpolating between the adjacent even scanlines. If you select Odd, then the odd scanlines will pass through unchanged into the output image while the even scanlines will be regenerated by interpolating between the adjacent odd scanlines.


Transformation Special Effects Posterize

Using Transformations

This command lets you render an image using a limited palette of colors -- a little like reproducing an image as a silk screened poster. Once you specify which palette colors you want to use, Picture Window scans the image and converts each pixel to the closest color.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Amount

The amount control lets you control how much of the posterize transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Number of Colors

This control lets you specify the number of colors that will be used to represent the input image. You can specify any number from 2 to 32.

Remap Colors

Turning on the remap colors option adds an extra level of options to the Posterize transformation. If the box is checked, then Picture Window displays an alternate color square next to each of the palette selected colors, and an extra step is introduced into the computation of the result image. As before, each pixel in the input image is scanned and the closest matching palette color is determined. Then, instead of making the output pixel the palette color, the alternate color is substituted instead.

Antialias

If you check the antialias box, Picture Window smooths out the sometimes jagged-edged, pixelized result of posterization by very precisely recomputing the result image at the boundaries between areas of different colors. This involves making a second pass over the data which generally takes somewhat longer than the first pass, but the resulting image has much softer edges. To speed up previewing, you may want to leave antialiasing disabled until the very end.

Auto Palette

If you click the Auto Palette button, Picture Window scans the input image and automatically selects a palette of colors that can represent the image reasonably well. It then sets the color controls (see below) for the color palette and the remap colors to the colors it selected. After selecting an auto palette, you can go on to modify any of the palette or remap colors to vary the results.

Colors

At the bottom of the Posterize dialog box Picture Window displays a small color square for each palette color. These color squares are arranged in as many rows of 4 as necessary. If Remap Colors (see above) is checked, a second, alternate color square is displayed next to each palette color square. To select or change a primary or alternate color, click on the corresponding color square to bring up a color picker window and use this to choose a color.

Hint: It is often very helpful to use the [image] button in the color picker to match a palette color to part of the input image.


Transformation Special Effects Grid

Using Transformations

This command lets you create a range of special effects from simple colored rectangles or rectangular cutouts to complex rectangular grid overlays. You can separately control the interior and exterior background colors and the number of major and minor horizontal and vertical grid subdivisions, and the major and minor line widths and colors.

Grid Rectangle

You select the grid rectangle by dragging the four corners, the four sides, or the interior of the crop box displayed over the input image. The grid divisions will be confined to the rectangle you specify.

For greater precision in setting the grid rectangle, remember you can zoom the input image window.

Input Image

The input image control displays a thumbnail of the input image for reference purposes.

Divisions

Using the Major Horizontal Divisions, Major Vertical Divisions, Minor Horizontal Divisions, and Minor Vertical Divisions controls, you can control the number of equally-spaced grid lines within the grid rectangle.

Line Width and Color

Using the Major Line Width and Minor Line Width controls, you can set the width, in pixels, of the major and minor grid lines. The Major Line Color and Minor Line Color controls let you set the colors of the major and minor grid lines.

Interior and Exterior Transparency and Colors

You can set the transparency of the interior and exterior of the grid rectangle by selecting Transparent Background, Colored Interior, Colored Exterior, or Colored Background. If the interior or exterior is not transparent, you can select its color with the Interior Color or Exterior Color control.


Transformation Texture

Using Transformations

This command is used to create an image window filled with a black and white textured background which is tiled (repeated) to fill the entire surface of the output image. By adjusting the texture controls, you can generate a wide range of different textures or you can tint the texture image using a color line control.

Textures are generated using random data that is altered using a mathematical technique called an inverse 2-dimensional Fourier transform. With a given set of settings, many different textures can be generated by starting with a new set of random numbers.

Randomize

Clicking this pushbutton causes a new set of random numbers to be generated and used to create a variation of the current texture. To see the results of this randomization, you must preview the output image.

Width, Height, and Resolution

These controls are used to set the resolution and size of the output image. By default, these settings are taken from whatever image window was the current window at the time the Texture transformation was invoked. The current texture tile is repeated as necessary to fill the entire output image.

Tile Size

This Popup List Control lets you choose the size of the texture cell that is repeated to fill the output image. The individual tiles can be repeated seamlessly (i.e. the pattern matches between the left and right edges and the top and bottom edges. Small tiles compute very quickly but generate a very regular pattern as the small cells must be repeated many times to fill a large image. Large tiles take longer to compute but do not repeat as often. On computers with less than 16MB of RAM, avoid choosing a tile size of 1024x1024.

Color Line

The Color Line Control lets you specify a color sequence that will be used to tint the texture cell. The color at the left end of the color line is applied to the parts of the texture image that are black; the color at the right end is applied to the parts of the texture image that is white. You can get some interesting effects by additing additional points to the color line and experimenting with the color line transition settings and the locations of the transition points.

Frequency

This double slider lets you specify what part range of frequencies to use when synthesizing a random textures. The black slider sets the lower limit and the white slider sets the upper limit. Lower frequency values affect the coarse structure of the texture; higher values create fine structure. If the lower limit exceeds the upper limit, then the range between the two is excluded instead of being included.

Angle

This double slider lets you specify the orientation of the texture. The black slider sets the lower limit and the white slider sets the upper limit. Only frequency components whose direction falls in the range between the lower and upper limit are used to synthesize the texture. If the lower limit exceeds the upper limit, then the range between the two is excluded instead of being included.

Power

This slider lets you alter the weighting of the power spectrum with respect to frequency. Lower values generate coarser textures; higher values generate more fine structure.

Modifying textures

You can use any of Picture Window's transformations to modify a texture image once you have created it. For example, you can warp, emboss, sharpen, blur, equalize, resize, or tint it, or apply a brightness or saturation curve to it. You can also create interesting effects by creating three different textures and using the Combine Channels transformation to turn them into a composite colored texture. Finally, you can combine two or more different textures using the filter, difference, or composite transformations.

Applying textures to an image

There are a number of different ways to apply a texture to an image. The first step is to generate a texture image that has the same dimensions as the image to which you wish to apply the texture.

Method 1: Using the Brightness Transformation

This technique can be used to lighten an image where the texture image is light and darken it where the texture image is dark.

Start by creating a black and white texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select the Brightness transformation. Then click on the white square to the right of the Amount control in the Brightness dialog box and select the name of the window containing the black and white texture image. Finally, experiment with different positions of the black and white sliders in the Amount control to get different effects.

Method 2: Using the Filter Transformation

This technique can produce the same effect as sandwiching the image with a texture image to combine the two.

Start by creating a black and white or colored texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select the Filter transformation. Then click on the white square to the right of the Filter control in the Filter dialog box and select the name of the window containing the texture image. Finally, experiment with different positions of the Amount and Exposure Compensation sliders, the Complement checkbox, to get different effects.

Method 3: Using the Composite Transformation

This technique can produce the same effect as making a double exposure of the image and a texture image to combine the two.

Start by creating a black and white or colored texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select the Composite transformation. Then click on the white square to the right of the Overlay control in the Composite dialog box and select the name of the window containing the texture image. Finally, experiment with different positions of the Overlay Amount slider and the Operation options, to get different effects.

Method 4: Using a Texture as a Mask

This technique can produce a wide variety of effects.

Start by creating a black and white or colored texture image whose dimensions match those of the image you want to texture. Then open the image you want to texture in a window, click on it to select it, and select Mask from the main menu. Then select the name of the texture image from the bottom of the Mask menu. This will place the texture over the image as a mask.

At this point, you can use this mask to selectively blur, sharpen, lighten, darken, or composite the image (see Using Masks with Transformations). Or you can use the freehand painting or retouching tools to generate textured painting or retouching effects (see Using Masks with Tools).

Other Uses for Textures

There are many other ways to use textures including:

1) Creating screens for use with the Halftone Transformation

2) Creating backgrounds for compositing (see the Composite and Layout transformations). The texture transformation can also be used as described above to apply textures to backgrounds generated using the Gradient transformation.

3) Creating distortion maps for use with the Displace Transformation

4) Creating masks for use with the Add NoiseTransformation


Transformation Layout

Using Transformations

This transformation is used to create an image that consists of a background page of a specified size overlaid with one or more panels. The background may be a solid color or tiled with (covered with multiple copies of) an image. Each panel may contain solid colors, images, and text and can be placed anywhere on the background with any size or transparency. The panels are like layers, and you can control the order in which they are applied to control how they overlap.

This transformation provides a very convenient way to create various page layouts for printing, slide shows, or presentations. And, layouts can be saved as templates and used again at a later time to create a consistent set of compound images.

A number of controls (described below) are displayed down the left side of the dialog box; the right hand side is used to display a preview of the final layout. This preview also has a ruler displayed in the current units along its top and left edges. The layout preview is automatically updated as you change the layout settings. The Layout dialog box can be resized to make this preview either larger or smaller.

Clicking on a panel in the layout preview causes it to become the current panel. The current panel is highlighted by a rectangular outline with small squares displayed at the corners. You can reposition or resize a panel by clicking and dragging its interior, corners, or sides.

To edit the properties of a panel, simply click on it with the right mouse button to bring up the Panel Properties dialog box.

Width, Height, and Resolution

These controls are used to set the resolution and size of the background image onto which the panels will be placed. You can specify the background size in pixels, inches, millimeters, or centimeters. You can only modify the Width and Height settings when no panels have been added since this can alter the proportions of the background and result in panels being shifted out of range. You can modify the Resolution setting, however.

If you modify the Resolution setting while the units are set to pixels, then the image size in pixels will remain unchanged and the image size in inches (or mm or cm) will be adjusted accordingly. If the units are set to inches (or mm or cm), then changing the Resolution setting will keep the physical dimensions of the image the same and adjust the image size in pixels accordingly.

Snap Grid

This setting lets you specify a grid interval to which all panels will be aligned when you reposition them using the mouse. To disable this feature, simply set it to 0. Using a snap grid makes it easy to precisely position and align panels on the background.

Background

This Color or Image Control lets you select how the background is colored. You can either select a solid color for the background or an image that will be tiled (repeated both horizontally and vertically as necessary) to cover the entire background.

Scale

This slider is used only when an image is selected for tiling the background (see above). In this case, adjusting the scale slider lets you vary the tiling pattern by making the tiled image either larger or smaller.

Tool Bar

The layout tool bar lets you perform a variety of operations by clicking one of the individual buttons:

 Add a new panel

Clicking on this icon adds a new panel to the current layout. This panel is initially set to a gray rectangle in the center of the background. In addition, an Panel Properties dialog box pops up to let you edit the properties of the panel.

 Remove the current panel

Clicking on this icon deletes the current panel (if any) and removes it entirely from the layout.

 Send panel back one layer

Clicking on this icon sends the current panel one level lower in the panel stacking order. This means that it can be partially or totally covered by another panel that sits on top of it.

 Move panel forward one layer

Clicking on this icon raises the current panel one level higher in the panel stacking order. This means that it can partially or totally cover other panels that are below it.

 Cycle through panels, one at a time

Clicking on this icon selects the next higher panel in the stacking order. If the current panel is the topmost level, then the bottom panel is selected.

 Center current panel horizontally

Clicking on this icon causes the current panel to be horizontally centered on the background.

 Center current panel vertically

Clicking on this icon causes the current panel to be vertically centered on the background.

 Shrink rectangle to fit image

Clicking on this icon causes the current panel to be reduced in size to match the dimensions of the image it contains.

 Create a grid of panels within the current panel

Clicking on this icon causes Picture Window to display the Create Grid Dialog Box. This dialog box lets you specify a grid layout of subpanels within the current panel (or within the background image if no panel is currently selected).

 Save current layout

Clicking on this icon pops up a standard File Save dialog box. Select the name of the file you want to save the layout in and click OK. Picture Window will ask you if you want to include images with the saved layout.

If you select Yes, the saved layout file will include the pathnames of the images (if any) currently used in the background and each of the panels. For more details about saving images in layouts, see the note below.

If you select No, image references will not be saved with the layout and the background and all image panels will come up blank when the save layout file is loaded.

 Load a saved layout

Clicking on this icon pops up a standard File Open dialog box. Select the name of the file you want to load and click OK. The current layout settings will be reset and the specified layout restored.

Important note about saving and loading layouts: Images that are included in a layout are saved by including their pathnames in the layout file. Untitled images (i.e. images that have not yet been saved) do not have pathnames and are not saved in the layout file. When attempting to reload a saved layout, an image of the same pathname will automatically be opened if it is not already open. If an image file having an exact match on the pathname cannot be found, Picture Window then searches for an image with the same filename in the directory containing the layout file. Therefore if you store the layout file and all of its related images in a single directory, Picture Window will be able to locate and reopen all of the included images, even if you move the directory to a different location on your hard disk, to a different disk drive, or to another computer.

Size and Location Readouts

At the bottom of the Layout dialog, the size and location of the current panel are displayed; if there are no panels or if the background is selected, the size of the background is displayed instead.

Creating a new Default Layout

If you use a certain layout frequently, you can configure Picture Window to make that layout the default each time you invoke the Layout transformation. If a file called Default.lyt exists in the Picture Window folder, then the Layout transformation loads this file on startup to establish its initial layout. If Default.lyt is absent or cannot be found, standard default settings are used to initialize the layout.

To create a default layout file, simply create or load the layout you want and save it under the name Default.lyt in the same folder Picture Window is in. By default, this is C:\Program Files\Digital Light & Color\Picture Window 2.5.


Create Grid Dialog Box

This dialog box lets you create a grid of subpanels within the current panel (or within the background image if no panel is selected). You can control the size of the subpanels, the number of columns and rows of subpanels, and the margins around the edge of the current panel (or background image).

The right hand side of the dialog box displays a preview of the current grid; this preview is only updated when you click the Preview button. If any of the settings is out or range or if the specified layout will not fit in the available space, an appropriate error message is displayed. When you are done, click OK to create the grid of panels or click Cancel to exit without creating any panels.

Panel Width/Panel Height

These controls let you enter the size of the subpanels in the current units.

Left/Right/Top/Bottom Margins

These controls let you enter margins for the panel (or background image) in the current units.

Columns/Rows

These controls let you enter the number of columns and rows of subpanels.


Panel Properties Dialog Box

The Panel Properties dialog box lets you control exactly what is displayed within a particular panel's rectangle. A panel can have one of three types of background: a solid color, an image, or it can be transparent. In addition, it may contain one or more lines of text which is superimposed over the background. Finally, the panel rectangle may be outlined with a border of a specified width and color.

Background

This control lets you select whether or not you want a transparent background.

Color/Image

This Color or Image control lets you select the background solid color or image, assuming you have not selected a transparent background (in which case these settings are ignored).

If you select an image, then a cropping rectangle is displayed over the input image. You can resize and reposition this rectangle by clicking and dragging its vertices, edges, or interior. Only the region outlined by the cropping rectangle will be applied to the panel.

Amount

This Amount control lets you select the transparency of the panel. You can either select an overall transparency or you can specify an amount mask to vary the transparency for different parts of the panel. If you selected a background image, the amount mask must have the same dimensions as the image; if you selected a solid background color, the amount mask can be any size.

Orientation Tool Bar

This tool bar lets you change the orientation of the panel's background image and text by rotating them in 90 degree increments. Simply click on the corresponding arrow icon to rotate the text and image accordingly.

Proportions

If you select Match image to panel, then Picture Window locks the proportions of the cropping rectangle of the image in the panel (if any) to those of the panel itself, thus avoiding any excess around the edges. This setting is the one to use if you want images to fill a specific size panel completely.

If you select Free, then you can adjust the proportions of the image and panel independently. In this case, the image may not fit the panel perfectly. Use this setting when you want to be able to adjust the proportions of the image cropping rectangle freely to accommodate different subject matter. When you are done adjsuting the crop box, you can use the [image]  button in the Layout dialog tool bar to shrink the panel to fit the image proportions to eliminate any excess.

Text

This multiline edit control lets you enter one or more lines of text which will be displayed over the panel background (if any). To enter multiple lines, type Enter at the end of each line. The orientation of the text is controlled by the Orientation tool bar (see above).

To transfer large amounts of text from a document or other program, you can copy the text onto the clipboard and then paste it into the Text control. To paste into an edit control, simply click on the control to make the cursor a caret (vertical line) and then press Ctrl-V. The text on the clipboard will replace all highlighted text at the caret location.

To enter special characters such as the copyright symbol into the Text control you can use the following procedure:

1) Bring up the Character Map application that comes with Windows.

2) Double click on the symbol you want to insert and then click the Copy button. This copies the symbol to the clipboard.

3) Go to Picture Window's text control and position the caret where you want to insert the symbol and type Ctrl-V (the shortcut for Paste).

If you prefer, instead of using the Character Map application you can use a word processor such as Microsoft Word to insert the desired symbols into a blank document and then copy them from there to the clipboard.

Note: If you select characters from the Symbol or WingDings fonts or any other font that does not use the standard alphabet, then you must select the same font in the Font control. The characters in the Text control are always displayed using the Arial font, so special characters may not display correctly within the control but will be OK when applied to the image. For this reason, it is usually more convenient to copy the copyright, trademark, registered, and other symbols from the Arial font than from the Symbol font.

The alignment of the text within the panel is controlled by the Alignment control (see below). To position text freely with respect to a background image, place the text in a separate panel and make its background transparent. You can then drag the text over the image to any desired position.

Font

This control lets you select which font the text will be displayed in. You can choose from any of the TrueType or Postscript fonts installed on your computer.

Font Size/Bold/Italic

These settings let you select a font size (in points) and select any combination of bold or italic. These settings adjust the size and appearance of the text.

Alignment

This control sets the justification and alignment of text withing the panel rectangle. You can select any combination of Left, Center, or Right with Top, Middle, or Bottom. Selecting Left, Center, or Right causes the text to be left justified, centered, or right justified; in addition, the block of text is aligned with the left edge, the center line, or the right edge of the panel rectangle. Selecting Top, Middle, or Bottom aligns the block of text with the top, center, or bottom of the panel rectangle.

Text Color

This Color control sets the color of the text.

Border Width

This settings lets you set the width of the border that will be drawn around the panel rectangle. To suppress the border, set the width to 0.

Border Color

This Color control sets the color of the border.


TWAIN

TWAIN is a standard jointly created by a number of companies involved in image capture and display to provide a standard interface to scanners, frame grabbers, digital cameras, and any other input devices capable of generating digital images. In TWAIN terminology, each input device is called a source.

When you purchase a TWAIN-compatible scanner or other device, it comes with its own TWAIN driver and instructions. Once you install the TWAIN driver, the source becomes available to any program that supports the TWAIN interface standard.

The process of using a TWAIN driver has two parts. First, if you have more than one TWAIN source installed, you must select the one you want to use with the File Select Source command. Next you initiate the actual scanning process with the File Acquire command. This causes the selected TWAIN driver to take control of the user interaction and lead you through the scanning process in a manner customized for the device you are using. For instructions on using the driver, you must refer to the documentation that was shipped with the input device, as each one is unique.


Color Spaces

Every visible colors can be specified by a set of three numbers. There are many different schemes for classifying all the possible colors. The three schemes that Picture Window uses are RGB, HSV, and HSL.

RGB (Red Green Blue)

The RGB color space breaks colors down according to the amount of each of the three primary colors they contain. Red, green, and blue are called additive primary colors because light of these colors can be mixed in different proportions to make any other color. Most computer equipment is based on the RGB color space and it is therefore the easiest for a computer to work with. Unfortunately, humans do not naturally interpret colors according to this system. The space of all colors in the RGB system is a cube.

HSV (Hue Saturation Value)

The HSV color space categorizes colors by their hue, saturation, and brightness (sometimes called value). Hue corresponds to the colors around the outside of the color wheel. Hues run from red to yellow to green to cyan to blue to magenta, and back to red.

Varying hue while keeping saturation and value at 100%

Saturation refers to the intensity of a color. A fully saturated color is very pure and deep; as you reduce their saturation, colors become progressively more washed out until at a zero saturation they become shades of gray.

Varying saturation with 0% hue and 100% value

The term Value refers to the overall brightness of a color. All colors with a value of zero, regardless of their hue or saturation, are black. As you increase value, colors become progressively brighter. The brightest, most saturated colors are those with the maximum value.

Varying value with 0%hue and 100%saturation

The space of all colors in the HSV system can be thought of as a hexagonal cone with black at the vertex. The following pictures are crossections through the hexcone at 50%, and 100% value. At 0%, it converges to a black point.

50%

100%

HSL (Hue Saturation Lightness)

The HSL color space categorizes colors by their hue, saturation, and lightness. As in the HSV color space, Hue corresponds to the colors around the outside of the color wheel and Saturation refers to the intensity of a color.

Varying hue with 100% saturation and 50% lightness

Varying saturation with 0% hue and 50% lightness

The term Lightness refers to the brightness of a color. All colors with a lightness of zero, regardless of their hue or saturation, are black. As you increase lightness, colors become progressively brighter. The brightest, most saturated colors are those with a lightness of 50%. As lightness increases toward 100%, colors become increasingly whiter. All colors with a 100% lightness are white.

Varying lightness with 0% hue and 100% saturation

The space of all colors in the HSL system can be thought of as a double-ended hexagonal cone with black at one vertex and white at the other. The following pictures are crossections through the double hexcone at 25%, 50%, and 75% lightness. At 0%, it converges to a black point and at 100% it converges to a white point.

25%

50%

75%

Complementary Colors

The complement of a color is the color you add to it to get a neutral gray. You can find the complement of a color by going half way around the color wheel. The following primary colors are complements:

Red and Cyan

Green and Magenta

Blue and Yellow

Subtractive Primary Colors

Cyan (a blue-green), Magenta (a red-blue), and Yellow are the subtractive primary colors you were taught about in grade school. You can mix any other color by combining paints or inks of these colors. The subtractive primary colors are just the complements of the additive primary colors, red, green, and blue.

CMYK

The printing industry uses a four-color system call CMYK (Cyan, Magenta, Yellow, Black) to print books, magazines and newspapers. They use the fourth color, black, because it is impractical to manufacture pure cyan, magenta, and yellow inks; mixing the real inks creates a dark muddy green instead of a pure black. Furthermore, printing presses have limits on how much ink coverage they can handle without smearing, using black ink reduces the total amount of ink required to print dark areas.

Halftoning

Since a printing plate is either inked or not inked, a printing press cannot reproduce a continuous range of gray levels directly. Photographs are printed using a technique call halftoning. This involves representing an image as small dots of different sizes. Dark areas have large dots that contain more ink and light areas have small dots with little ink.


Mask

A mask is a black and white image used to identify part of another image. A mask must have the same exact width and height in pixels as the image it is used with. Masks serve the following purposes:

To protect part of an image from being modified by a tool like clone or paint

To localize the effects of a transformation to part of an image

To identify those parts of one image to be composited with another

While any black and white image of the correct size can be used as a mask, the most common ways to create a mask are with the Mask Command or the Gradient Transformation

Creating Masks

Mask Dialog

Using Masks with Transformations

Using Masks with Tools

Masking Tips


Creating Masks

A mask is a black and white image used to select, identify, or protect part of another image.

To create a new mask for an image

First select the image you want to mask by clicking on it. Then execute the Mask New command from the main menu or click on the [image] icon on the tool bar. This creates a new and initially clear mask overlay for the image and pops up the Mask dialog This dialog provides tools you can use to modify the mask overlay.

To apply an existing mask to an image

A mask image must be a black and white image and it must have exactly the same width and height in pixels as the image to which it is applied. First make sure that both the image and the mask are open in separate windows. Then select the image you want to mask by clicking on it and then execute the Mask command from the main menu. Select the name of the mask image you want to use from the list of available masks at the bottom of the Mask menu. This makes the mask image into an overlay for the original image and pops up the Mask Dialog This dialog provides tools you can use to create or modify the mask overlay.

Masks

Mask Dialog

Using Masks with Transformations

Using Masks with Tools

Masking Tips


Using Masks with Transformations

Many of Picture Window's transformations can be used with masks; the mask serves to limit the effect of the transformation to a particular region of the input image. For example, you can create a mask that consists of a black circle on a white background and use this mask to brighten or darken just that circular region of an image. Masks can also contain shades of gray, so you can control exactly how much of a particular transformation to apply to each part of an image.

To select a mask before running a transformation

Use the Mask New command to create a new mask or apply an existing mask to the input image before running the transformation. When you run a transformation, the mask will automatically be selected as the amount mask for the transformation.

To select a mask after running a transformation

Select the transformation from the Transformation menu. If the transformation accepts an amount mask, you will see a slider with a large button to its right:

Click on the button to pop up a menu of available masks and select the one you want to use by name. A thumbnail image of that mask will appear on the button face.

Using the amount double slider

Once you have selected a mask as an amount mask, the amount slider changes from a single to a double slider; one black and the other white.

The white slider controls what percent of the transformation is applied to the input image in regions where the mask image is white. The black slider controls how heavily the transformation is applied where the mask is black. Gray parts of the mask produce an intermediate effect.

Initially the white slider is set to 100% and the black slider to 0%. This means that the parts of the input image where the mask is white receive the full force or the transformation while black areas remain untouched. At the other extreme, when you reverse the positions of the black and white sliders, you invert the effect of the mask, applying the full transformation to the parts of the input image where the mask is black and leaving the white areas untouched.


Using Masks with Tools

Picture Window's clone, paint, and miscellaneous tools can be used with masks; the mask prevents part of the input image from being affected by the tool. For example, if you create a mask that consists of a white circle on a black background, you can use this mask to protect that circular region of an image while you paint around it. Since masks can also contain shades of gray, you can control exactly how much of a particular tool is applied to each part of an image.

To use a mask with the clone, paint, or miscellaneous tools

Create a mask overlay on the input image before selecting the tool.

Masked regions are fully protected from the action of the tools; unmasked regions are totally unprotected. Partially masked regions are partially susceptible to the tools.

You may find it useful to temporarily suppress the mask overlay while using the tools so you can see the input image better (see Mask Display under Mask Dialog).


Mask Dialog

The mask dialog is a dialog window containing the masking controls. These controls let you create or modify a mask for a particular input image.

To qualify as a mask for an input image, an image must have the same width and height in pixels as the input image and must be a black and white image.

Before you start to use the mask dialog, select the input image window by clicking on it. Then either select Mask New from the Mask menu or select the name of an existing mask from the list of possible mask images end of the mask menu. This will pop up the mask dialog.

The caption bar of the mask dialog identifies the name of the input image window.

All, None, Invert

Clicking All masks the entire input image. Clicking None clears the entire mask. Clicking Invert reverses the masked and unmasked areas by taking the negative of the current mask.

Area...

Clicking this button causes Picture Window to compute the area of the input image that is currently covered by the mask. The result is reported both as a number of pixels and as a percentage of the total image area of the input image. Pixels that are partially masked are counted as fractions, so the pixel total may not be an integer.

Undo

Clicking Undo reverts the mask to its state just preceding the last mask operation.

Cancel, OK

Clicking Cancel aborts the mask session and discarding the changes to the current mask. Clicking OK peels the current mask overlay off of the input image and places in back in an image window as a black and white mask image.

Mask Mode

The mask mode controls how the current mask will be modified by new mask element you create. New mask data can augment, diminish, overlap, or invert the current mask:

Clicking [image] causes new mask data to be added to the current mask. Use this mode to create or extend a masked region.

Clicking [image] causes new mask data to be subtracted from the current mask. Use this mode to trim a masked region.

Clicking [image] causes the current mask to remain in effect only where it overlaps new mask data. Use this mode where you want to create a mask based on two conditions being met simultaneously, for example, to create a mask consisting of all pixels in a certain region and with colors in a certain range.

Clicking [image] causes the current mask to be inverted where new mask data is present. Use this mode to reverse part of a mask.

Mask Overlay Color

The current mask is displayed as an overlay on the input image. You can set the color of the overlay to red, blue, green, or white by clicking the button of the corresponding color.

Mask Display

Picture Window can display mask overlays in a number of different ways.

Clicking [image] causes the mask to be displayed as a semitransparent layer whose color you set with the mask overlay color buttons. This is the default mode of operation and lets you see both the image and the mask at the same time. Depending on the colors in the input image, changing the mask overlay color may make the mask easier to see.

Clicking [image] causes the mask to be displayed as an opaque layer whose color you set with the mask overlay color buttons. This mode makes it the mask more visible at the expense of obscuring the masked parts of the input image.

Clicking [image] suppresses the input image, letting you see the mask overlay displayed in black and white without the input image.

Clicking [image] suppresses the mask, letting you see the input image with no mask overlay.

Mask Tools

Picture Window supports a powerful set of masking tools. You can draw masks freehand, create oval or polygonal masks, mask by color range, feather the edges of a mask either inward or outward, or one combine two or more masks with each other.

Clicking [image] enables the freehand drawing tool.

In this mode, you start by clicking on the input image and, holding the mouse button down, drawing the outline of the region you want to mask. When you release the mouse button, the endpoint of the outline is automatically connected to its starting point and the entire interior of the outlined region becomes the new mask object. This object is then combined with the current mask according to the current mask mode. If the [image] mode is selected, for example, each region you outline is added to the current mask. If you accidentally mask part of the image you want to leave unmasked, just switch to [image] mode and outline the region you want to remove.

Clicking [image] enables the rectangle drawing tool.

In this mode, you click on one corner of a rectangle in the input image and, holding the mouse button down, move the cursor to the diagonally opposite corner. When you release the mouse button, the rectangle you have selected is outlined. You can click and drag the sides, corners, or interior of the rectangle to reposition it if necessary. To create a square region, hold down the Shift key while dragging the sides or corners of the rectangle.

When you click Apply, the selected rectangle is combined with the current mask according to the current mask mode. If the [image] mode is selected, for example, the outlined region is added to the current mask.

Clicking [image] enables the oval drawing tool.

In this mode, you click on one corner of a rectangle in the input image and, holding the mouse button down, move the cursor to the diagonally opposite corner. When you release the mouse button, an oval filling the rectangle you have selected is outlined. You can click and drag the sides, corners, or interior of the rectangle to reposition it if necessary. To create a circular region, hold down the Shift key while dragging the sides or corners of the rectangle.

When you click Apply, the selected oval is combined with the current mask according to the current mask mode. If the [image] mode is selected, for example, the outlined region is added to the current mask.

Clicking [image] enables the polygon drawing tool.

In this mode, you click on one corner of a rectangle in the input image and, holding the mouse button down, move the cursor to the diagonally opposite corner. When you release the mouse button, the rectangle you have selected is outlined. Once you have created this initial rectangle, you can modify it by adding or removing vertices. To add a new vertex, shift-click (while holding down either Shift key, position the cursor and click once with the left mouse button) near the side of the polygon connecting the two vertices you want to insert between. To remove a vertex, control-click (while holding down the Ctrl key, click once with the left mouse button) on it. There must always be at least three vertices to define a polygon. To reposition a vertex, simply click and drag it; to reposition the entire polygon, click and drag the handle displayed at the center of the polygon.

When you click Apply, the selected polygon is combined with the current mask according to the current mask mode. If the [image] mode is selected, for example, the outlined region is added to the current mask.

Clicking [image] enables the spline drawing tool.

A spline is a smooth curve that passes through a specified set of control points.

In this mode, you click on one corner of a region in the input image and, holding the mouse button down, move the cursor to the diagonally opposite corner. When you release the mouse button, the region you have selected is outlined. Once you have created this initial region, you can modify it by adding or removing control points. To add a new control point, shift-click (while holding down either Shift key, position the cursor and click once with the left mouse button) near the line segment connecting the two control points you want to insert between. To remove a control point, control-click (while holding down the Ctrl key, click once with the left mouse button) on it. There must always be at least four control points to define a region. To reposition a control point, simply click and drag it; to reposition the entire region, click and drag the handle displayed at the center of the region.

When you click Apply, the selected region is combined with the current mask according to the current mask mode. If the [image] mode is selected, for example, the outlined region is added to the current mask.

Clicking [image] enables the mask feathering tool and pops up additional feathering controls:

Masks created as freehand outlines, for example, have hard edges. Feathering can be used to soften the edges of a mask or to expand or shrink the masked region.

Feather Width

Feather width specifies the distance in pixels that mask edges will be extended. Positive values extend a mask outward making the masked region larger. Negative values extend the current mask inward making the masked region smaller.

Falloff

Gradual falloff softens the edge of a mask by causing it to fade gradually across the feather width. Sudden falloff grows or shrinks a mask by extending it inward or outward by the feather width.

Corners

Round corners extends mask edges in a circle; Square corners extends mask edges in a square.

Click Apply to feather the current mask.

Clicking [image] enables the color range tool and pops up additional controls:

You can set Color Space to RGB, HSV, or HSL. Depending on the color space you select, the three color controls are labeled accordingly. If the input image is black and white, then there will be only a single control for gray level.

Each color component has two pairs of sliders you can adjust, one white and one black. The white sliders adjust the range of values for that component that are fully selected; the black sliders control how suddenly the selection falls off for values outside the white range. The gray scale below the color stripes illustrates the extent to which colors will be selected for each color component. Where the scale is white, pixels with those values will be fully selected; where the scale is black, pixels will be deselected; where the scale is gray, pixels will be partially selected.

Three markers short vertical lines show the values of the three color components for pixels in the input image. As you move the cursor over the input image with the mouse button down, these markers are continuously updated. The color stripes reflect how this probe color varies as you change one color component leaving the other two fixed. In the example above, the H (Hue) stripe shows that an orange pixel has be selected and shows how the color changes as the hue component is varied. Similarly for the saturation and value components.

When you click Apply, Picture Window computes the set of pixels in the input image that fall within the ranges you have specified and this becomes the new mask object. This object is then combined with the current mask according to the current mask mode.

When you click Contract, Picture Window shrinks the ranges down to just include the color indicated by the three markers. As you move the cursor over the input image, holding down the shift key and depressing the left mouse button, the current ranges are automatically expanded just enough to include the colors the cursor is passing over.

Clicking [image] enables the paint tool and pops up additional controls:

When the paint tool is active, clicking on the input image and moving the cursor  with the left button down spray paints on the mask. The Radius, Transparency, and Softness sliders adjust the characteristics of the brush, a representation of which is displayed at the bottom of the Mask Dialog. Depending on the current Mask Mode, painting can add to or subtract from the current mask.

This tool is similar to the outline tool except that it paints with a soft edge, and it does not fill the interior of the path the cursor moves over.

Clicking [image] enables the combine tool and pops up additional controls:

Clicking on the large button pops up a list of possible mask images that you can combine with the current mask. When you select one, a thumbnail version of the mask image is displayed on the button face.

When you click Apply, the selected mask image becomes the new mask object. This object is then combined with the current mask according to the current mask mode.

Clicking [image] enables the brightness curve tool and pops up additional controls. This tool lets you select regions of an image based on their brightness.

The curve control at the bottom of the dialog box lets you select what part of the tonal range of the image to select. To higher the curve value for a given brightness level, the more it will be selected in the mask. The curve above creates a mask that fully selects white pixels and gradually trails off to deselect black pixels.

When you click Apply, the selected mask image becomes the new mask object. This object is then combined with the current mask according to the current mask mode.

Masks

Creating Masks

Using Masks with Transformations

Using Masks with Tools

Masking Tips


File Formats

Picture Window supports most common image file formats.

TIFF

TIFF stands for Tagged Image File Format. This format is very versatile and is supported across many different computing platforms. TIFF is an excellent choice both for general image file storage and for exchanging images with Macintosh or UNIX computers. The one problem with TIFF format is that, due to its great generality, it has many variants and this gives rise to occasional incompatibilities between files generated by different applications.

There are many variations of TIFF files, some of which incorporate lossy or lossless compression. The TIFF files Picture Window writes are lossless and not compressed. Picture Window should be able to read most TIFF variations.

TIFF is the only format that supports both 16-bit black and white and 48-bit color images. (Pro version only)

BMP and RLE

BMP stands for bitmap. This is a Windows-specific file format which is supported by nearly all applications that run under Windows and deal with images. If you are not concerned with cross-platform compatibility, BMP is a perfectly good choice. BMP files are lossless and not compressed. RLE files are a variant of BMP which incorporate run-length encoding, a simple method of lossless compression that does a good job of compressing large areas of solid color. Unfortunately, 24-bit color images cannot be saved in RLE format without first being reduced to 256 colors, so RLE is not a good format for saving color images.

JPEG

JPEG stands for Joint Photographic Experts Group. This is a standard image file format supported by multiple computing platforms. JPEG format differs from the other formats listed here in that it allows for variable levels of file compression that involve discarding information from the image that cannot later be reconstructed. JPEG is excellent for archiving images or compressing them for distribution or electronic transmission, but it should be avoided in cases where the image will be reprocessed as this may amplify compression artifacts (see JPEG). The JPEG file format is supported by Web browsers and is a good choice for placing photographic images in Web pages.

Targa, PCX

Targa and PCX formats are general purpose image file formats supported by various other programs and platforms, but now largely obsolete.

GIF

GIF stands for Graphics Interchange Format. This format was developed for use on CompuServe to compress images for electronic transmission. The GIF file format is supported by Web browsers and can be used to place images in Web pages. It works especially well for those images containing large areas of solid color since these are compressed without loss of information. Since GIF does not support 24-bit color and Picture Window supports only 24-bit color, images must be reduced to 256 colors before saving them as GIF files. For this reason, saving and reloading a color image as GIF will degrade its color information and therefore GIF format should not be used to archive color images.

PNG

This format was developed as a replacement for GIF. It supports all image types and work across different platforms. PNG is one of the file formats proposed for use on the World Wide Web. PNG (pronounced “PING” files support a lossless compression scheme similar to that used to compress GIF files.

FlashPix

The FlashPix format was developed primarily by Kodak for use in their digital cameras and consumer scanning services. Its main advantage is that you can read a small piece of an image file or a low resolution version of an image without reading the entire file. FlashPix files may be uncompressed (lossless) or optionally compressed using JPEG . Importantly, FlashPix files include viewing information such as monitor gamma that makes them more portable across different platforms and programs than most other formats.

EPS

EPS stands for Encapsulated PostScript. This is a format developed by Adobe for inclusion in Postscript documents. Picture Window supports this format for output only. This file format is not generally very useful.

FITS

The FITS format was developed to help exchange scientific data sets. It is somethimes used to store astronomical images and supports both 8-bit and 16-bit black and white images. There is currently no standard for encoding color images as FITS files.

PhotoCD

The PhotoCD file format was created by Kodak for storing scanned images on CD-ROM. Except when reading Corel image disks, the best way the read PhotoCDs is the use the File Open PhotoCD command. Picture Window supports this format for input only. Photo CD files are compressed using a nearly lossless scheme.

AVI

AVI stands for Audio Video Interleaved and is the Windows standard format for storing video information. It provides for synchronized streams of interleaved images and sound stored within a single file.


JPEG

JPEG stands for Joint Photographic Experts Group. The JPEG committee has published a widely supported standard technique for compressing photographic images. JPEG compression can usually reduce the size of an image by a factor of 5 to 15 with little or no visible degradation. To see for yourself how good JPEG really is, try saving an image in JPEG format and then reloading it into another window so you can compare the compressed/decompressed version with the original.

JPEG Artifacts

Unlike certain lossless techniques, JPEG compression reduces the storage necessary to represent a color or black and white image by discarding information, not all of which is redundant. This means that after compressing and then decompressing an image, the result is not identical to the original. The differences, called artifacts, can become noticeable under certain conditions which you need to understand.

The most important way to reduce JPEG artifacts is to select a high quality level when you save the image. This reduces the amount of information discarded and leads to higher image quality; unfortunately, it also reduces the compression ratio. The default quality level of 97% produces excellent results in nearly all cases while retaining fairly good compression.

Sharpening an image after compressing and decompressing it greatly exaggerates JPEG artifacts. Certain other operations such as embossing also have a similar effect.

Repeated cycles of JPEG compression and decompression can accumulate errors that gradually degrade an image.

Don't use JPEG to save intermediate images

For these reasons, if you are storing an image which you will later work on (especially if you plan to sharpen it) you should use one of the lossless file formats such as TIFF or BMP. On the other hand, JPEG compression is an excellent file format for archiving images or for preparing them for electronic distribution or transmission.


White Point

The White Point of a monitor is the color it produces when displaying a signal whose red, green, and blue values are all set to their maximum. Like other light sources, monitor white points are sometimes reported by their color temperature. Most computer monitors have a very high color temperature (over 9000) which is distinctly bluish. If uncorrected, this imparts a bluish cast to all displayed images. Standard daylight-corrected light boxes or viewing booths have a color temperature of around 5000 which is much less blue.


Luminance

Luminance refers to the perceived brightness of a color. Since the human eye is much more sensitive to some colors than others, the luminance of a color is computed as a weighted average of its red, green, and blue components:

Luminance = 0.30*Red + 0.59*Green + 0.11*Blue


Color Control

A color control consists of a text label and a colored button. The color of the button face is the currently selected color. Clicking on the button pops up a color picker which you can use to modify the current color or select a new color altogether. Simply close the color picker when you are done.


Popup List Control

A popup list control consists of a text box with a [image] button to its right. Clicking on this button (or anywhere else on the control) brings up a popup list with the current selection highlighted. Either select a new item while holding the mouse button down or release the mouse with the cursor outside the menu to retain the current selection.


Histogram

A histogram is a graph which represents the relative amounts of different brightness levels in an image. A histogram is computed by looking at all the pixels of an image and keeping track of how many pixels have each brightness level. The histogram runs from dark at the left and increases to the right.

The histogram of a dark image peaks at lower gray levels while the brightest levels may read zero; a light image peaks at higher gray levels. The first gray level to contain a spike represents the darkest pixels in the image; the last gray level to contain a spike represents the lightest pixels in the image.

An image that represents a dark object on a light background will have two peaks; one in the dark areas corresponding the object and one in the lights corresponding to the background. The relative sizes of the peaks are proportional to the relative areas of the object and background.

For an image to use the full available dynamic range effectively, its histogram must have information distributed across the entire gray scale.

To view the brightness histogram of an image use Brightness Curve ; to view the Saturation histogram of an image, use the Color Curves Transformation.

Curve Control


PhotoCD

PhotoCD is a system developed by Kodak for digitizing and storing 35mm negatives or slides on compact disks. If it is equipped with a PhotoCD-compatible CD-ROM drive, your computer can read images from these disks.

PhotoCD Permanence

Kodak has taken special precautions to ensure that PhotoCDs will not deteriorate. To quote from a Kodak white paper on the topic of PhotoCD permanence: "It is reasonable to expect a life of 30 years or more when discs are stored in normal home or office conditions." Of course, your biggest problem 30 years from now may be finding a working CD-ROM drive.

Creating PhotoCDs

You can either have a PhotoCD made from your film at the same time it is developed or you can have a disk made from a set of slides or cut negatives. You can also have images added to an existing PhotoCD; this creates a so-called multisession disk. Although most newer CD-ROM drives are multisession compatible, some older drives only read single session disks. PhotoCD services are available world-wide from a range of providers.

Image Resolution and Print Quality

Each PhotoCD holds approximately 100 high quality color images, and each image is stored on the compact disk in resolutions from 128x192 pixel low resolution thumbnails all the way up to 2048x3072 high resolution images. Each increasing step in resolution has 4 times as many pixels as the one before, so the memory size of these images increases rapidly.

The most useful resolution for most amateur photographers is probably 1024x1536. Images of this resolution are around 4MB, but still contain enough information to make very good 8x10 prints. The next lower resolution, 512x768 can make good 4x5 prints and uses only around 1MB. The highest resolution images, 2048x3072, are almost 19MB each. These images are difficult to work with unless you have a very fast computer with lots of RAM, and the increased quality is barely visible in an 8x10 print.

Professional PhotoCD

Kodak has released a professional version of its PhotoCD mastering equipment that can handle transparencies and negatives up to 4x5. The Pro PhotoCD format support a new super-high resolution of 4096x6144 which uses 75MB per image. Scanning at this resolution is time consuming and most professional scans now cost at least $20 per image.

PhotoCD Scanning Tips

PhotoCD Service Providers

PhotoCD-compatible CD-ROM drives


Viewing Conditions

Viewing conditions in the room you work in greatly influence the appearance of colors on your monitor. To achieve accurate, repeatable results, you must calibrate your monitor and observe the following viewing conditions:

The room you work in must have very subdued illumination. Bright light falling on the screen will wash out bright colors and totally eliminate shadow detail. If you cannot get your workspace really dark, a viewing hood that fits over your monitor may help.

Choose a monochrome desktop color scheme (you can do this with the Color and Desktop Control Panels from the Windows Program Manager). Colored window borders, text, wallpaper, or backgrounds can distort your perception of color images.


Color Picker

The color picker window lets you select a color based on the HSV color space. The dialog looks like this:

Clicking on the hexagonal color wheel in the middle of the dialog selects hue and saturation. Clicking on the slider at the right of the dialog selects value.

Clicking on one of the color bars at the lower right selects hue and saturation corresponding to black, 25% gray, 50% gray, 75% gray, white, red, green, blue, cyan, magenta, or yellow.

At the bottom of the color picker dialog box, Picture Window displays the numeric values of the three color components of the currently selected color in the RGB, HSV, or HSL color space. The value of each component is scaled to a number between 0.0 and 100.0. You can enter numeric values into these controls to select colors directly -- After a short delay, Picture Window changes the numbers you enter to those that correspond to the closest matching color. In the HSV or HSL color spaces, there are situations in which the color you request may not be available.

A special version of the color picker is displayed in circumstances where a gray level is being specified instead of a color. This color picker has no color wheel, only a brightness slider.

The three color patches at the lower left display the currently selected color against black, gray, and white backgrounds.

Clicking the [image] button lets you choose from the following options:

Full

This option displays the full color wheel as shown above.

Pastel

This option displays an enlarged view of the central portion of the color wheel which is where the less saturated, pastel colors are located. This option is useful for selecting more subtle colors.

Filter Bank

This option displays a scrolling palette of colored buttons corresponding to all the standard CC and Wratten filters, each labeled with its filter number. You can use these buttons to select a color equivalent to the color of one of more of these filters.

The CC (color correction) filters come in six series, one for each primary and secondary color: Cyan, Magenta, Yellow, Red, Green, and Blue. Each series of filters is referenced by its optical density from 0.025 to 0.90. For example, a CC10R is a red filter with a density of 0.10.

Wratten filters come in a miscellaneous set of colors and are simply referenced by their filter number. The use of these filters is explained in many photography texts.

Clicking on more than one filter button is like stacking the selected filters. To deselect a filter, simply click on it a second time; the currently selected filters are indicated by their buttons being displayed as depressed. To reset all the buttons and return the selected color to white, click the Reset button at the bottom of the color picker dialog box.

Probe Size (1x1/3x3/5x5/7x7/9x9)

These options let you control the sample size used by the probe, should you choose to enable it (see below). Larger probe sizes are useful for obtaining an average reading of any area of the image that does not have a smooth texture; smaller probe sizes let you get precise readings of very small areas. The currently selected probe size is shown with a check mark.

To choose a color by pointing to part of an image window, click on the [image] button and then click on the image whose color you want to sample. You can vary the probe size from the options menu (see above).

To terminate the color picker, close its window by double-clicking on the icon in its upper left corner.


PhotoCD-Compatible CD-ROM Drives

Most CD-ROM drives more than two years old will not read PhotoCDs as they are recorded using mode 2 which is normally used for recording audio rather than data. Some of the drives that read mode 2 data are not multisession compatible. The first time you have images transferred to a PhotoCD, a single session disk is returned to you. If you had less than the full 100 images transferred to the PhotoCD, this leaves a lot of empty space on the disk. When you resubmit your disk to have more images added to it, the second batch of images is stored as a new session. If you have a single session PhotoCD drive, you will be unable to access the images in the second session. A multisession drive can read all the images on a multisession disk; the disk looks to the computer just like a single session disk, with all the images in one unbroken sequence.

Multispeed CD-ROM drives have recently started to displace the older, single-speed drives. These drives run at normal speed when playing audio, but can speed up when reading data.

Unless your CD-ROM drive is very old, it almost certainly multisession PhotoCD-compatible.


PhotoCD Service Providers

You can have a PhotoCD made in one of two ways. The least expensive per image is to have the disk made at the same time your film is developed because they can feed the film through the scanner automatically by its sprocket holes before it is cut into strips or mounted as slides. The least expensive per useful image, however, is usually to save up your best pictures and have them individually transferred to disk.

What kind of film to use?

Both slide and print film have their pros and cons for making PhotoCD scans.

Scanning Slides

When you have slides scanned, the resulting PhotoCD reproduces the color balance of the original slides quite faithfully. However, there is a problem when scanning very dark shadow areas on transparency film as the scanner cannot resolve detail when the film density of the slide exceeds 2.8. You can use Picture Window to overcome this problem if you bracket your exposures by scanning both light and dark versions of a slide to disk and combining them after the fact. (see Extending the dynamic range of slide film) Also, when you scan from slides, the corners of your images may be slightly out of focus due to the curvature of the film in the slide mount.

Scanning Negatives

Since print film has a narrower density range it does not have the problems with shadow detail that affects slide scans, but the PhotoCD workstation does perform the same kind of automatic color balancing and exposure adjustment as is done by automatic print making machines when they make conventional prints. Often the resulting scans come out fine, but sometimes the images are poorly color balanced or exposed. Again, you can use Picture Window to correct these problems if they are not too severe.

In either case, use fine-grained films whenever possible. Scans made from very grainy films such as Scotch Chrome 1000 do not faithfully reproduce the grain structure of the original image.

Locating a PhotoCD service provider

The easiest way to locate a PhotoCD service provider is via Kodak's web site (http://www.kodak.com). They maintain a searchable database of all PhotoCD suppliers.

PhotoCD Resolution

The highest resolution (18MB) PhotoCD images resolve about 40 lines per millimeter on the film which is somewhat less detail than is actually present on most films (for example, Ektar 25 has a theoretical resolving power of about 160 lines per mm). Kodak's new professional PhotoCD workstation scans at twice the resolution and will handle film formats up to 4x5", but the highest resolution images are then 75MB which is too much data to handle gracefully on most of today's personal computers. Professional scans are also much more expensive ($20 to $30 each).


Amount Control

Most of Picture Window's transformations contain an amount control that defines how much of the transformation is applied to the input image. The amount may be set to a constant value, in which case the transformation is applied uniformly to the entire input image. Or, the amount may be set to a mask image which lets you confine the effect of the transformation to either the masked or unmasked areas of the input image. The amount control has three parts: a large square button, a readout, and a single or double slider.

Amount Button

When you click on the amount button, a menu pops up consisting of Constant, optionally followed by a list of mask image names. If the amount is Constant, the face of the button is painted with a solid gray whose brightness is proportional to the amount value. If the amount is a mask, the face of the button displays a thumbnail of the mask image.

If the button face contains a miniature image, then clicking the right mouse button on the button brings the window that contains the image to the top and restores it if it is minimized.

Readout

The amount readout displays the current setting of the amount slider.

Single Slider

If the amount control is set to Constant then the slider has a single black indicator which you can use to set the amount value. Setting an amount of 0% causes the transformation to have no effect at all; the output image is identical to the input image. Setting the amount to 100% causes Picture Window to apply the transformation at full strength to the entire input image when computing the output image. A value of 50% yields an output image that is a 50-50 blend of the input image and what the output image would be if the amount were 100%.

Double Slider

Setting the amount control to a mask splits the marker into two parts, one black and one white. The black slider controls the amount value associated with parts of the mask image that are black; the white slider control the amount value for the white parts. The amount values for different gray levels in the mask image are intermediate between the amount levels for black and white. For example, if the black slider is set to 0% and the white slider is set to 100%, then where the mask image is white, the transformation will be applied fully and where it is black the input image will be unchanged. Where the mask is gray, the effects will be partial. Reversing the black and white sliders is like inverting the mask: the transformation is applied to the unmasked rather than the masked regions. As for the single slider, setting intermediate amount values for the two sliders lets you apply the transformation partially.


Color or Image Control

This control is used to select either a single solid color or a color image. It consists of label text with a large square button to its right. If a single color is currently selected, the button face assumes that solid color. If a color image is selected, the button face displays a thumbnail of that color image.

Clicking on the button pops up a menu containing the item Constant Color, optionally followed by a list of image names.

Selecting Constant Color brings up a Color Picker you can use to select a single color.

If the button face contains a miniature image, then clicking the right mouse button on the button brings the window that contains the image to the top and restores it if it is minimized.


Perspective Correction

When you take a photograph of a subject like a building with your camera tilted upward, the vertical lines of the building converge toward the top of the image. This effect, sometimes called keystoning, is often considered undesirable as it makes the building look as though it is leaning backward. The process of making converging verticals parallel is called perspective correction. Conventionally, this is done either by using a special perspective control lens, or by using a view camera whose lens and or film plane can be shifted. You can use Picture Window to correct perspective using the Warp transformation.


Curve Control

Curve controls are used by the Brightness Curve and Color Curves transformations. A curve control lets you specify a curve that converts one set of levels to another. For each pixel in the input image, its level is computed and then converted by the curve to a new level which is used to compute the output image.

A curve control consists of a large graph on the left and a set of option buttons on the right. The graph can take one of two forms: a curve display with a histogram in the background or a histogram display with a curve in the background. The two graphs are different views of the same information.

Points

Initially, the curve is defined by two points connected by a straight line. You can move points by clicking and dragging them. You create a new point by Shift-Clicking on the curve or histogram; you delete a point (other than the first or last point) by Control-Clicking over it. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other; to Control-Click, hold down the Ctrl key while you click the left mouse button)

Curve Display

When the graph is set to curve display, the curve is in the foreground. A gray scale is displayed along the horizontal axis which corresponds to levels in the input image. Another gray scale is displayed along the vertical axis which corresponds to levels in the output image. Each point is displayed as a small square on the curve. You move points by dragging them, create points by Shift-Clicking on the curve, and delete points by Control-Clicking on the curve. For each point, an arrow is also displayed on each axis corresponding to that point's x and y coordinates. You can adjust only the input level or output level of a point by dragging the corresponding arrow.

Picture Window can connect the points with different kinds of curves. It can use a smooth curve, a broken line, or a stair step curve. The curve type is selected by option buttons (see below).

Histogram Display

When the graph is set to histogram display, a pair of histograms is in the foreground. The input image histogram is displayed on top, and an inverted output image histogram is displayed on the bottom. For each point on the curve, an arrow is displayed under the input histogram at its input level, and an arrow is displayed above the output histogram at its output level. The two arrows are connected by a line. You move points by dragging their arrows, create points by Shift-Clicking on the upper histogram, and delete points by Control-Clicking on the upper arrow. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other; to Control-Click, hold down the Ctrl key while you click the left mouse button)

This display not only shows the input and output histograms, but it also graphically represents how each part of the gray scale is compressed or expanded or shifted. If a pair of lines converges from top to bottom, then that range of grays is compressed (local contrast is decreased); if they diverge, the range is expanded (local contrast is increased). If the lines slant to the left, then the range is shifted toward black; if the lines slant right, the range is shifted toward white.

 pops up an options menu which includes the following items:

Reset returns the curve control to its initial state.

Invert inverts the curve, replacing each output value by its negative.

Load lets you reload a previously saved curve from a disk file.

Save As lets you save a curve in a disk file for future use.

Linear Histogram displays histogram using linear scaling. Linear scaling provides the most visually accurate representation of the histogram.

Log Histogram displays histogram using logarithmic scaling. When using linear scaling, if the histogram has a very strong spike in can cause the lower values to be scaled down so much that they are hard to read. Log scaling compresses the dynamic range of the display by exaggerating smaller values and making large spikes less dominant.

Probe Size (1x1/3x3/5x5/7x7/9x9)

These options let you control the sample size used by the probe (eyedropper), should you choose to enable it (see below). Larger probe sizes are useful for obtaining an average reading of any area of the image that does not have a smooth texture; smaller probe sizes let you get precise readings of very small areas. The currently selected probe size is shown with a check mark.

 changes the graph to Curve Display.

 changes the graph to Histogram Display.

 connects the points with a Stair Step curve.

 connects the points with a Broken Line curve.

 connects the points with a Smooth Curve.

 activates the probe (eyedropper). This lets you click on pixels in the input image and see their level. Picture Window displays a red line on the curve or input histogram that moves as you move the cursor over the input image window with the mouse button depressed. This in turn lets you relate the curve or histogram to different parts of the input image. You can use the options menu to set the probe size (see above).

Curve Examples


Thumbnail

A thumbnail is a miniature version of an image used for identification purposes.


Color Line Control

This control lets you choose a sequence of points along a line, controlling the location and color of each point and how the colors transition from one point to the next. Color line controls are used to define gradients or to define a color sequence for tinting black and white images. The transformation dialogs that contain color line controls are normally resizable. By widening the dialog box, you can elongate the control to gain finer control of its color sequence.

A color line is displayed as a color strip with numbered tic marks above it and buttons below it:

To move a point, simply drag its marker or number. The first and last points cannot be moved.

To add a new point, Shift-Click on the color strip where you want the new point to appear. (To Shift-Click, hold either Shift key on the keyboard down with one hand while you click the left mouse button with the other.)

To remove a point (other than the first or last point which can not be removed), Control-Click on its marker or number. (To Control-Click, hold either Ctrl key on the keyboard down with one hand while you click the left mouse button with the other.)

To change the color of a point, Double-Click its marker or number. This pops up a Color Picker you can use to select the color of the point.

To alter the characteristics of the transition between two points, click on the button displayed between them, below the color strip. This pops up a menu offering you the following transition options in two groups:

Step Left makes an abrupt transition at the left point.

Step Center makes an abrupt transition halfway between the two points.

Step Right makes an abrupt transition at the right point.

Line makes an even transition from one point to the other.

Sine makes a transition that varies more gradually near the two points and faster in the middle.

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RGB computes transition colors in RGB color space.

HSVCW computes transition colors in HSV color space, with hue increasing clockwise from the first point to the second.

HSVCCW computes transition colors in HSV color space, with hue increasing counterclockwise from the first point to the second.

HSLCW computes transition colors in HSL color space, with hue increasing clockwise from the first point to the second.

HSLCCW computes transition colors in HSL color space, with hue increasing counterclockwise from the first point to the second.

Clicking the [image] button pops up a menu of options containing the following items:

Reset resets the color line to its initial settings.

Load lets you restore a previously saved color line from a disk file.

Save As lets you save a color line as a disk file.

Rainbow Gradients


Scanner

A scanner is a device which converts slides, negatives, or prints to a digital form. Scanners vary in type, resolution, accuracy of registration, dynamic range, and scanning speed.

Types of Scanners

A transparency scanner passes a highly focused beam of light through your film and reads how much red, green, and blue light is transmitted at each pixel location. A reflective scanner works by bouncing light off of a print or other object and measuring the color of the reflected light. In either case, the resulting image contains a set of three numbers for each pixel, one for red, green, and blue.

Resolution

Image sharpness is mainly determined by the resolution of the scanner. Transparency scanners normally require much higher resolution than reflective scanners because film is so much smaller that a print. The more pixels the scanner captures, the finer the detail it can reproduce. Scanner resolution is usually reported in dots per inch (dpi).

Color Registration

A color scanner really makes three separate scans of your image; one for the red channel, one for the green channel, and one for the blue channel. This is usually accomplished either by making three passes over the image with different color filters or by making a single pass with a light that can change colors very rapidly. In any case, it is very important that the three scans be precisely aligned with each other. Registration errors lead to visible color fringes that parallel edges in the image. (see the Registration transformation)

Dynamic Range

For a scanner to capture the full dynamic range of the image on the film or print, the range of its light sensors must exceed that of the image data. The CCD sensors used in less expensive scanners have a smaller dynamic range than the photomultiplier tubes used in the high-end drum scanners used for commercial prepress work. This can lead to loss of shadow detail in some cases.

Scanning Tips


Monitor

A monitor is another name for the display screen on your computer. The face of a color monitor is covered with clusters of tiny red, green, and blue dots. These dots give off light when struck by a beam of electrons which sweeps across the screen in a raster pattern, from left to right and from top to bottom.

Monitors vary in size, usually measured by their screen diagonal. Other important characteristics are maximum resolution, refresh rate, and dot size. More expensive monitors can display high resolution images (1024x768 and above) at high refresh rates. Refresh rates less than about 70Hz cause visible flicker which is not only annoying but can lead to eye strain. High resolution in itself does not necessarily mean the image is sharp. Dot size, which is mainly related to size of the holes in the shadow mask on the face of the screen, is really a better indicator of image sharpness. The smaller the dot size, the better the image quality.

Good monitors have low distortion, good color purity, and produce even illumination and sharp focus across the entire screen.

The resolution, refresh rate, and color depth of your monitor are controlled by the display adapter in your computer.


Gamma

Gamma is a technical term that refers to the curve that relates the RGB component values of a pixel to the actual image brightness, as measured off the face of the monitor by a photometer. Since the human visual response is nonlinear, it is desirable to set the gamma curve to roughly match that of the eye. This is approximated by using a mathematical relationship called a power law where gamma is the exponent.

The standard gamma value used in television sets, PhotoCD, and most PC computer monitors is 2.22. This is the value used in Picture Window’s File Calibrate command. Other standard gamma values in common use are 1.8 (the prepress standard) and 1.4 (the Macintosh standard).

You can use Picture Window to adjust the gamma of an image with the Gamma Adjust transformation .


Resizing, Zooming, and Scrolling Windows

You can resize an image window, a preview window, and some transformation dialog windows. Resizable windows are displayed with a thick border.

You resize a window by dragging any of its corners or sides.

You can zoom image and preview windows.

To zoom a window, use the Window Menu or one of the zoom icons on the Tool Bar.

If you zoom or resize an image window to the point where the entire image cannot be displayed, then the window is drawn with scroll bars you can use to pan the window across the image.


Using Transformations

Only one transformation can be active at a time. If you try to start a new transformation while another transformation is already active, the transformation menu items are grayed out.

To use a transformation:

1)	Select the input image by clicking on it.

2)	Select the transformation you want to perform from the Transformation menu. Picture Window will then display a Transformation Dialog. A dialog is a window containing controls you can use to enter settings.

Transformation dialogs are modeless. This means that, while the dialog is active, you can still use other windows. For example, you can use tools and/or masking without first shutting down a transformation.

Most transformations let you preview their effect in a preview window. Since the preview window usually has lower resolution than the input image or is restricted to a small part of the input image, or both, it generally takes much less time to compute than the final transformation on the entire image at full resolution. This lets you experiment with different transformation settings quickly.

You can resize, zoom, and scroll preview windows. This lets you trade off between preview speed and preview image size. You can zoom in and see a preview at high resolution of a small part of the result image or you can zoom out and see a low resolution preview of the entire image.

Along the top of most transformation dialogs are Auto, Preview, Apply, OK, and Cancel buttons.

If you check Auto, Picture Window automatically recomputes and redisplays the preview window each time you change any of the transformation settings.

Clicking Preview tells Picture Window to compute and display a preview of the transformation with the current settings. This button is grayed out when Auto is checked or if the current preview image is already up to date.

Clicking Apply causes the current transformation settings to be applied at full resolution to the input image to generate the final output image which is then placed in a new window. At this point you can either terminate the transformation by clicking Cancel or you can change one or more of the transformation settings and click Preview or Apply again. In any case, the input image is never modified and remains intact.

Clicking OK causes the current transformation settings to be applied at full resolution to the input image to generate the final output image which is then placed in a new window. Next the transformation dialog box is closed along with the preview window and any other windows related to the transformation. The input image remains intact. Clicking OK is equivalent to clicking Apply followed by Cancel.

Clicking Cancel abandons the current transformation, closing the transformation dialog window, the preview window, if any, and any other windows related to the transformation. The input image remains intact.

Switching Input Images

Most transformations include an Input Image control which displays a miniature of the currently selected input image:

When you click on this miniature image, Picture Window pops up an image menu from which you can select any currently open image window that is a valid input image for the current transformation. If the image you want to operate on is not in a open window, you can use the File Open command to open it without closing the transformation dialog box. To select a new input image, simply click on the corresponding item in the image menu.

Clicking the right mouse button on the miniature image brings the current input image window to the top and restores it if it is minimized.

By switching input images and using the Apply button, you can perform identical transformations on multiple images. This is particularly useful in situations like cropping or warping both an image and its mask image(s) or to color correct a series of images consistently using the same filter or color balance settings.

Using Masks with Transformations


Curve Examples

Curves are created with a Curve Control. The following examples illustrate the relationship between a curve and its effect.

No-Change

This curve makes the output level the same as the input level; applying this curve leaves the input image unchanged; any curve near this curve will have only subtle effects.

Negative

This curve makes the output level the negative of the input level; applying this curve makes low levels high and high levels low; any curve near this curve will have similar effects.

Boost Middle Levels

Applying this curve increases all levels, especially the middle levels. High and low levels are changed less.

Decrease Middle Levels

Applying this curve decreases all levels, especially the middle levels. High and low levels are changed less.

Increase Midlevel Contrast

Applying this curve increases all high levels and decreases low levels; this increases contrast in the middle of the range and reduces contrast at high and low levels..

Decrease Midlevel Contrast

Applying this curve decreases all high levels and increases low levels; this decreases contrast in the middle of the range and increases contrast at high and low levels..

Posterize

Applying this curve maps the full range of input levels into just a few different output levels.

Solarize

Applying this curve makes an image that is part negative, part positive. Any curve that reverses its slope from positive to negative or vice versa will produce the distinctive solarization effect.


Solarization

Solarization is the process of altering an image so that part of its gray scale is reproduced positive and part negative.


Posterization

Posterization is the process of greatly reducing the number of colors or shades of gray used to representing an image. The name refers to a graphic technique often used to make posters with solid areas of a limited number of colors.


Display Adapter

A display adapter is the part of your computer that connects to your monitor. Normally, this is a card that plugs into your computer although in some cases it may be built into the motherboard. The display adapter is responsible for generating the video signal that creates the screen image.

Different display adapters have different characteristics and, depending on the driver that comes with the display adapter, your adapter may be capable of running in several different modes.

Resolution

Resolution is normally 640x480, 800x600, 1024x768, or greater. The higher the screen resolution, the finer the detail and the more images you should be able to view at once, subject to the limitations of your monitor's screen size and dot size. While Picture Window is perfectly usable at 640x480, higher resolutions are definitely better. Display adapters that support higher resolutions are more expensive because they contain more memory and must access that memory faster.

Number of Colors

Display adapters typically support 16, 256, 32,000 or 65000, or 16 million colors. This corresponds to 4, 8, 16, or 24 bits per pixel of color information. To view photographic images and to calibrate you monitor, you will need to set your display adapter to 24-bit color (16 million colors).

Refresh Rate

Better display adapters support higher refresh rates. A refresh rate of 70Hz or greater is required to avoid annoying screen flicker. Older monitors may limit the refresh rate of the display adapter.

Acceleration

Better display adapters are accelerated. This makes Microsoft Windows run much faster when it is displaying information on the screen.


Colorizing black and white photographs

You can colorize a black and white image using the paint tool. Before you can paint color over a black and white image, however, you must first convert it to color with the Convert Transformation.

Next, bring up the paint tool and select one of the Hue and Saturation Only options. Select the hue and saturation you want to paint with using the color setting. Painting over an area then adds hue and saturation while leaving the brightness information in the black and white image showing through.

Another technique that affords more control is to create a mask for each area in the black and white image you want to tint. You can then use the filter transformation to colorize that region using a solid filter color of your choice. This method gives you more control over the color than using the paint tool because you can adjust the mask and the color until you get exactly the results you want.


Lightening or Darkening an Image

Color Space

When lightening or darkening a color image, you should be aware that the results depend on the color space you use. To lighten an image by small or moderate amounts while keeping the image as saturated as possible, choose HSV. To lighten an image greatly or to make lighter colors tend toward white, use HSL. Avoid lightening with RGB, as this not only reduces saturation but also alters hues.

Freehand Methods

The freehand methods listed below let you lighten or darken an image by painting with the mouse.

Miscellaneous Tools

The miscellaneous tools let you lighten or darken an image freehand. For best results, use a large, soft brush and build up the effect you want gradually. For more control, try one of the transformation-based methods below.

One-to-One Cloning

To lighten or darken an image freehand using the clone tool, first use one of the transformation methods listed below to create a lighter or darker version of the image you want to modify. Then activate the clone tool, click on its options button, and select One-to-One. Now you can clone from the modified image over the original image to lighten or darken specific areas. Or, you can clone parts of the original image back into the lightened or darkened version of the image.

Transformation Methods

The transformation methods listed below let you lighten or darken by adjusting sliders. You can select an area of the image to lighten or darken by using these transformations with an amount mask.

Levels and Color Transformation

The Levels and Color transformation lets you adjust the shadow, midtone, and highlight brightness of an image. This is the simplest transformation for lightening and darkening.

Brightness Transformation

The Brightness transformation lets you adjust the overall brightness of an image. The advantage this transformation is that in a single operation you can lighten some parts of an image while darkening others.

Brightness Curve Transformation

The Brightness Curve transformation lets you adjust the brightness of an image by setting a brightness curve. The advantage of using this transformation is that you have very precise control over the way different gray levels are affected. Also, you can simultaneously adjust brightness, contrast, and dynamic range.


Rotating an Image

To rotate an image by a multiple of 90 degrees

Use the Mirror/Rotate transformation.

To rotate an image by an arbitrary angle

Use the Warp transformation. Click on its options button and select Rigid. Then drag one of the corners of the warp region to rotate and scale the warp grid without altering its proportions. For example, to make a horizon line horizontal, just rotate the grid until it lines up with the horizon in the image and click OK. Remember, you can zoom, resize, and scroll the image to position the grid precisely.


Cloning Tips

Clone tool

To activate the clone tool, either select Clone from the tools menu or click on the [image] icon on the tool bar.

When the circles overlap

When the circle you are cloning from overlaps the circle you are cloning to, Picture Window performs additional processing to avoid recycling the same image data over and over. This involves searching the undo buffer for the current stroke, so undo must be enabled for this feature to work. The one drawback is that the processing time keeps going up, the longer your stroke. To maintain good responsiveness when the circles overlap, try to keep your strokes short.

Removing specks, facial blemishes, and other small defects

Shift-click over a nearby part of the image of the right color and texture. Select a brush radius comparable to the defect size and use intermediate values for transparency and softness. Position the cursor over the defect and hold the mouse button down while moving the cursor around to paint over the defect.

Removing scratches, telephone wires, etc.

Removing scratches is a little trickier than removing isolated defects. The most effective technique is usually to shift-click on a spot very near the scratch, but displaced slightly to one side or the other. Then carefully paint along the scratch.

Removing entire objects

To remove an object, you must recreate the background that it obscures. This can either be very easy or nearly impossible, depending on the image. Foliage and other backgrounds with a random texture or smooth backgrounds like sky are relatively easy to clone from adjacent areas. To avoid obvious repetitions of background elements, use a number of different reference points when filling in a large area.

Cloning near edges

It requires special care to clone over an edge without disturbing it. First shift-click over another part of the same edge with the same orientation and background and then click over the part of the edge you want to alter.

Cloning with a mask

You can use a mask to protect parts of an image from the effects of the clone tool. See Using Masks with Tools.

Cloning one-to-one

This option, available from the option menu, is very useful for cloning from one version of an image to another version of the same image, since it forces the reference point into precise alignment with the cursor. This lets you paint part of one version over the other without worrying about misalignment between the two images. You can turn any transformation into a freehand brush; just apply the transformation to an image and clone the result back one-to-one over the input image wherever you want.


Masking Tips

Masks

Mask Dialog

Creating Masks

Inverting a mask

In the process of creating a mask, you may find it useful to reverse the masked and unmasked regions with the Invert button to help visualize the masked region.

Working from rough outline to detail

To mask a complex region, start by making a crude mask of the entire region with the outline tool, then zoom in and refine the mask by adding or removing small amounts at a time around the edges.

The range tool

The range tool is very useful for creating a mask based on the color of a region of the input image.

Filling pinholes in a range mask

When you create a mask with the range tool, it may have small pinholes. You can fill these quickly by painting over them with the mask paint tool using an opaque, hard-edged brush.

Creating a mask that isolates shadow, midtone, or highlight areas

To create a mask that isolates the parts of an image that have a certain range of gray levels, use HSV or HSL color space and use the white sliders to bracket the main part of the gray scale you want to select. Then pull the black sliders out to feather the effects of the mask over adjacent gray levels. You can use the resulting mask with various transformations to alter the color or brightness of the shadows, midtones, or highlights of an image.

Optimizing performance

The range tool works faster if you first isolate a region with the outline tool and then switch to overlap mode. This lets Picture Window ignore areas outside of the outlined region when applying the range tool.

Feathering

Feathering is very important especially when using masks with transformations. If you don't feather the edges of a mask, then the boundary between the transformed and unmodified regions of the input image will often be very obvious. Feathering blends the effects of the transformation around the edges and creates a more natural result. The larger the feather radius, the more the edges of the mask are feathered.

You may find it useful to save a copy of your mask before feathering. This lets you go back and refeather the mask after trying it out.

For most transformations that adjust brightness and color of an image, gradual feathering that falls off out from the regions you are modifying usually creates the best results (4-10 pixel radius).

When using the composite transformation, a smaller feather radius (1 to 4 pixels) usually works better.

When using the blur transformation to remove grain from the sky, try using the range tool to select the sky region and then feather with a negative radius and sudden falloff to avoid blurring the horizon line or any foreground elements silhouetted against the sky.

To feather a mask more than is possible using the feathering tool, you can use the Blur transformation with the Gaussian option and a large radius.


Rainbow Gradients

Gradient transformation

Color line control

You can create rainbow gradients with the color line control in the gradient transformation. Set both the starting and ending colors to red; then click on the button below the color strip and the transition to HSVCW. This creates the following effect:

You can then use the other controls in the gradient transformation to apply this gradient along a line or in a circle or oval.


Color Balancing Tips

Color Balance Transformation

Highlight casts are the most important

The human eye is more sensitive to bright colors than to dark colors. For this reason, highlight color casts are the most important setting. In most cases, you can use a highlight cast alone to do all of your color balancing.

Using the midtone probe

Some images, especially those scanned from color negatives have pure white highlights, but have a color cast in the midtones. To remove this type of cast, set highlight to none and set probe to midtone. Then click on a part of the input image that should be neutral to set the midtone color to remove. Finally click Preview to check the results; if necessary probe again and repreview.

Correcting for fluorescent lighting

Fluorescent lights often introduce a greenish cast to photographs. Removing this cast, especially from scans of color negatives, often requires use of a midtone cast as well as a highlight cast. Set your highlight cast first to get the image highlights the right color, then work on the midtones. In an image with mixed fluorescent and other lighting, you may have to create a mask to isolate the areas illuminated by different light sources and balance them separately.

Adjusting dynamic range

To adjust the dynamic range of an image, first set highlight and shadow to auto and bring up color pickers for the highlight and shadow casts to add by clicking on their respective color patches. To increase the dynamic range, move the value slider of the highlight color picker up and the slider of the shadow color picker down. This makes the highlights brighter and the shadows darker. Moving the sliders in the opposite directions reduces the dynamic range of the image.

Applying consistent color balance changes to several images

Adjust the first image and then use the Save As option (via the [image] button) to save the color balance settings in a file, then you can reload the settings for use with other images.

Color matching to a reference image

If you want, for example, to match a skin tone from one image to a skin tone in another image, all you have to do is select the skin tone in the input image as the highlight cast to remove and the skin tone you want to change to as the highlight cast to add. The procedure for doing this is as follows:

Set shadow and midtone balancing to none.

Select the highlight probe and click on the input image to select the skin tone as the highlight cast to be removed.

Click on the color square for highlight cast to add; this pops up a color picker. Click on the eyedropper icon in the color picker.

Click on the skin tone you want to match; this sets the highlight cast to add.

Color Balance transformation


Vignetting

Vignetting is the process of gradually fading an image around a central subject. You can fade the image to white, to black, or to any other color. There are two steps to vignetting an image.

Creating the mask

The first step is to create a mask that defines the parts of the image to be preserved and the parts to be faded. The softness of the mask edge defines how gradually the vignette will fade.

To create a circular or oval vignette, use the Gradient transformation.

To create a vignette that follows the outline of part of the image, use the outline tool in the Mask Dialog to isolate the subject and then feather or blur the mask with a large radius.

Applying the mask

Once you have created your mask, there are many different ways to vignette an image.

To vignette using the Filter transformation, select the mask as the filter image. Where the mask image is white, the image will show through unchanged; where it is darker, the image will be darkened. You can brighten the image, if necessary, with the exposure compensation setting.

To vignette with the Composite transformation, set the overlay to the solid color you want to fade to and select your mask as the overlay mask image. By adjusting the overlay amount double slider, you can control which parts of the input image are preserved and which parts are faded.

To vignette with the Brightness transformation, set the color space to HSL and select the mask as the amount mask. Set the amount double slider to leave part of the image untouched (set to 50%) and part to be lightened or darkened (100% or 0%). This will vignette either to white or to black. You can achieve a similar effect with the Brightness Curve transformation.


Memory

Photographic images contain large amounts of information and storing this information uses up lots of memory. When you run short, Windows attempts to create free memory by saving data to the swap file on your hard disk. While this can slow down your system considerably, it is not a fatal problem. However, if there is insufficient swap space, you may get an Out of Memory error from Picture Window. Normally Windows uses the empty space on your primary hard disk for swap space, so if you disk is almost full, you run the risk of getting Out of Memory errors.

Windows allocates memory for a number of different purposes. First Windows itself along with any drivers you have loaded uses several megabytes of memory. Next disk caching programs can tie up additional megabytes of memory. Finally, the Picture Window program occupies about a megabyte of memory. So, even before you start to load images, a good deal of your memory is already used up.

For every open image window, Picture Window allocates memory for the image data in contains. The image file size (see the Window Info dialog) gives you a pretty good idea of the amount of space occupied by an image. In addition, another version of this image at screen resolution is maintained so the display can be repainted efficiently. The size of this image depends on the size of the window. You can reclaim this memory by minimizing the window.

The easiest way to save memory is to close image windows you are not actively using, making sure to save any images you want to use later.

Working with smaller images requires less memory than working with larger images. This means that cropping your images early in the process of working with them will save memory. You can also use the Resize transformation to reduce the resolution of your images and save memory.

Finally, if you are using the paint, clone, or miscellaneous tools, the undo feature can place substantial demands on your memory if you have multilevel undo enabled. Try switching to single level or disabling undo completely if you are low on memory (see the File Preferences command).


Matching Monitor and Print

Unfortunately, there is no such thing as an absolutely match between a computer monitor and a color print. There are several reasons for this:

Prints look different in different light.

We have optimized our color matching and calibration for D5000 illumination, the most widely used standard in the graphic arts/photography industry. Most high quality light boxes and commercial viewing booths use this illumination. Viewing prints under incandescent light, fluorescent light, or in direct sunlight will alter their appearance to varying degrees as will the intensity of the illumination and even the color of the background you view the prints against.

Printer and monitor color gamuts are different.

The range of colors a color printer can reproduce, called its color gamut, is different from the range of colors a monitor can display. This results from physical differences between the dyes used by the printer and the phosphors used in the monitor. These differences show up mostly in certain very saturated colors. For the most part, the printer produces images that are a little more saturated, contain far more detail, and have a larger dynamic range than a monitor can display.


Dynamic Range

The dynamic range of an image is the spread of brightness levels between its darkest pixels and its lightest pixels. The higher the dynamic range, the higher the contrast.


Zoom Factor

The zoom factor is the ratio between screen pixels and image pixels. The current zoom factor of an image window is displayed in its title bar.

At a zoom factor of 1:1, each pixel in the image is displayed as one pixel on the screen.

At a zoom factor of 2:1, the image is magnified by replicating each pixel to a 2x2 square; at larger zoom factors, the image is magnified to a greater extent by making each pixel larger.

At a zoom factor of 1:2, the image is reduced by displaying every other pixel; at smaller zoom factors, the image is reduced further by omitting more pixels.

When you zoom an image in, you increase its magnification by increasing the zoom factor by 1. When you zoom an image out, you reduce its magnification by decreasing the zoom factor by 1.

To zoom in, use the Zoom In or the Zoom In and Resize commands.

To zoom out, use the Zoom Out command.

To set the zoom factor to a specific magnification or reduction value, use the Zoom Factor command.


Composite Examples

Using Composite with a solid color overlay

This blends the input image with a solid color overlay. You can either vary the transparency of the color overlay uniformly over the entire image or you can apply the overlay only to selected parts of the input image. The composite transformation is similar to making a double exposure; to simulate placing a colored filter over some or all of an image, use the Filter transformation.

To composite with a solid color, click on the Overlay button and choose Solid Color. This pops up a color picker you can use to select the overlay color.

To blend the color overlay with the entire input image

Use the Amount control to select the opacity of the overlay. A 50% level gives a 50-50 blend of the input image with the overlay color; 100% gives the overlay only and 0% gives the input image only. Blending with a light color over the entire image gives a result like haze or a uniform light leak in your camera. Blending with a dark color darkens the entire image.

To blend the color overlay with part of the input image

Create a mask for the input image that isolates the parts of the image you want to overlay. Select this mask into the Amount control. Use the double slider to select the opacity of the overlay over the masked and unmasked regions of the input image. Intermediate values blend the overlay color with the input image; blending with a dark color is a good way to darken parts of an image. Using a hard-edged mask, you can get results like pasting opaque cutouts of colored paper over the input image.

Using Composite with an overlay image

This technique lets you overlay one image over another. You can vary the transparency of the overlay image using the Overlay Amount control, and you can also restrict the effects to certain parts of the input image with the Amount control. Finally, you can also shift, rotate, scale, and/or skew the overlay image to make it line up with the input image.

Start by selecting the overlay image into the Overlay control.

By making the overlay image semitransparent, you get effects like a double exposure. By using a hard-edged mask to control the overlay transparency, you get an effect like a collage or photomontage. You can even place an overlay object "behind" an object in the input image by using two masks: one for the input image and another for the overlay image.

Overlay image and input image are the same size

This case is a lot like overlaying with a solid color (see above), except that you are now overlaying with a color image instead. Use the Amount control to set the opacity of the overlay image. Intermediate values give a blend of the two images. You can use a mask to selectively overlay different parts of the input image with different amounts of the overlay image. The Amount mask selects at each point the proportions of each image to blend into the result. A soft mask blends the images smoothly; a hard mask makes abrupt transitions between the images.

Overlay image and input image are different sizes

This case is a little more complicated because you need to define where to place the overlay over the input image as well as its opacity. To overlay an object in the overlay image with the input image, first create a mask for the overlay image that isolates the object you want to overlay and then select the mask as the Overlay Amount mask. Use the double slider to vary the opacity of the object and the background, and position the object over the input image using one or more Alignment points. To place the object behind an object in the input image, create a mask for the object in the input image and select it into the Amount control. This mask protects parts of the input image from the effects of the transformation.

For example, to overlay an image of the moon over a photograph of a mountain, start by creating two masks: one that precisely covers the moon in the overlay image and one that covers the silhouette of the mountain in the input image. Select the mountain mask into the Amount control, the image of the moon into the Overlay control and the moon mask into the Overlay Amount control. Adjust the double sliders as necessary to get the result you want. You can position the moon anywhere you want in the input image and even vary its size and orientation by selecting 2-point alignment.


PhotoCD Scanning

For the most part, a PhotoCD scan of a slide or negative will be an accurate representation of the film image. However, there are times when the results may be less satisfactory.

Grainy film

PhotoCD scans do a poor job of reproducing grainy images since the size of the grain particles is comparable to or smaller than the resolving power of the scanner. The result is a sort of mottled effect which has a very different texture from film grain. You can get the effect of normal film grain by scanning film that is less grainy and using a transformation such as Add Noise to add grain to the image before printing.

Dense slides

Current PhotoCD scanners do not always capture image data in transparencies when the density of the film is too great. This means that there can be some loss of shadow detail in very dark slides. Since most color negative film never gets as dense as a transparency, this problem is largely restricted to slides.

Color negatives with a strong color cast

Most of the time, PhotoCD scans of color negative film come out fairly well color balanced. However an image with a strong color cast may confuse the scene balancing software in the PhotoCD workstation. For example, the strong reds of a Santa Claus suit or the strong greens of a landscape that does not also contain blue sky can cause serious problems. In these situations, the PhotoCD workstation can mistakenly interpret these strong colors as an aberration in lighting or processing that needs to be removed, resulting in an image that is very poorly color balanced. In these cases, you can use the Color Balance transformation to restore normal color balance.

PhotoCD


Troubleshooting

Configuring the Number of Colors and Resolution of Your Display

Out of Memory Errors

PhotoCD problems

JPEG problems

Display problems

File Open problems

Printing problems

Scanning problems

DLL Conflicts


Configuring the Number of Colors and Resolution of Your Display

Your screen is controlled by a display adapter card installed in your computer. This display card in turn works with a Windows display driver to send visual information to your monitor. Most display adapter cards (also called video cards) can be configured to run with different numbers of colors and resolutions.

The number of different colors your screen can display depends on the number of bits used to represent each pixel:

Bits	Number of Colors
1	2
2	4
4	16
8	256
15	32,768
16	65,536
24	16,777,216

Some display drivers support 32-bit color -- this is in fact the same as 24-bit color with one additional unused byte per pixel. Adding to the confusion, some video cards are advertised as supporting 64 or even 128 or more bit operation. This refers to the type of microprocessor chip on the video card that accelerates certain graphics operations, not the number of bits per pixel.

The more colors your video card can display, the more accurately it can represent photographic images on screen. Operating in 24-bit (16.7 million) color mode ensures the best possible image quality. Using 15- or 16-bit color is almost as good, but some banding (abrupt color changes) may be visible is areas of smoothly varying color such as clear blue skies. Using 8-bit (256) color requires a technique called dithering to reproduce a full range of colors and this both makes images appear coarse and distorts their color.

Note: Changing the number of displayed colors has no effect on the quality of the underlying images or the way they will look when printed, just their appearance on the screen.

The term resolution refers to the dimensions of the screen area in pixels. For example, a resolution of 640x480 indicates that the display area consists of a rectangle 640 pixels wide by 480 pixels tall. Higher resolutions commonly used in Windows include 800x600 and 1024x768. The higher the resolution, the more image data you can view at once and the more detail each window can hold. Although 640x480 is usable, 800x600 is a definite improvement. To take full advantage of resolutions of 1024x768 and above requires a 17 inch or larger monitor.

Larger numbers of colors and higher resolutions each require larger amounts of video memory. This video memory is separate from the main memory used by your computer to run programs and store data. Video memory is used exclusively to display information on your monitor. Most display cards with 1 megabyte (MB) of RAM can operate at a resolution of 640x480 with 24-bit color or 800x600 with 16-bit color. In order to display 24-bit color at a resolution of 800x600, you will need a video card with 2MB of RAM. Cards with 3 or more MB of video RAM can display 24-bit color at a resolution of 1024x768.

To reconfigure your display driver

First select Settings/Control Panel from the Start menu, then follow the steps below.

1)	Double click on the Display icon in Control Panel and click on the Settings tab at the top of the Display Properties dialog box.

2)	Adjust the Color Palette setting to True Color (24-bit) if possible. If your driver does not support this, select the highest setting it does support, preferably at least 16-bit color.

3)	Adjust the Desktop Area slider as large as possible. The maximum size you can select depends on the amout of video memory on your display adapter (see above).

4)	Set the Font size setting according to your preferences. Small Fonts usually works best but may be harder to read.

To install a new display driver

First select Settings/Control Panel from the Start menu, then follow the steps below.

1)	Double click on the Display icon in Control Panel and click on the Settings tab at the top of the Display Properties dialog box.

2)	Select the button labeled Change Display Type.

3)	Select the Change button located to the right of the current selection in the Adapter Type dialog.

4)	Select the Have Disk button within the new dialog box.

5)	Insert the driver disk for your video card in the disk drive, enter the letter of the drive, and press the OK button.

6)	Select the driver you wish to install from the list that appears. Normally the various display drivers are named in such a way as to give you some idea of the resolution and number of colors they support.

Windows will install the new driver, then inform you that you must restart Windows for the changes to take effect. If you do not restart Windows, the changes will take effect the next time you start Windows.

For additional information about the Control Panel, or assistance installing a new driver, see the Adding or Changing a Device Driver For Hardware topic in Windows Help.


Out of Memory Errors

Why Out of Memory errors happen

Photographic images contain a great deal of information and storing this information uses up lots of memory. Windows also allocates memory for a number of other purposes. First Windows itself along with any drivers you have loaded use several megabytes of memory. Next disk caching programs can tie up additional megabytes of memory. Finally, you need room for the programs you are running and the documents you are working on. So, even before you start to load images, a good deal of your memory is already used up. When you run out of memory, Windows uses virtual memory to provide additional storage space by saving inactive data to a swap file on your hard disk. While this can slow down your system considerably, it is not a fatal problem. However, if your swap file is too small, you will get an Out of memory error.

About the Windows Swap File

The Windows swap file is a hidden file on your hard disk. This file expands as necessary when programs that are running request additional memory. This means that if the disk containing the swap file is full or nearly full, you will have very little swap space available and thus you will be likely to get "out of memory" errors. Windows lets you place limits on the size of your swap file should you wish to guarantee a minimum amount of available virtual memory or keep the swap file from eating up all the free space on your hard disk.

To increase the amount of available virtual memory, you must free up space on the hard drive that contains your swap file by deleting other files you do not need. Or, if you have more than one hard drive, you can switch the swap file to another drive that has more free space.

Checking the Memory Status

To see how much swapfile space you are using and how much you have left, select the Help/About Picture Window command from the main menu. The currently available free and available swap space are displayed at the bottom of the About box.

Changing your Swap File Settings

To view or modify your swap file settings, you first select the System option in the Windows Control Panel. Then click on the Virtual Memory button. This brings up a dialog box that lets you specify which hard drive (if you have more than one) will be used for swapping and the minimum and maximum swap file sizes. After modifying your virtual memory settings, you must restart Windows for the changes to take effect.


PhotoCD problems

Problems reading some PhotoCDs

If you are getting errors or your computer is crashing while trying to access some or all of your PhotoCDs, double click on the System Windows Control Panel, click the File System button, click on the CD-ROM tab, and set the Optimize access pattern for control to No read-ahead.

Problems reading high resoloution Images from certain PhotoCDs

Some commercial PhotoCDs are created as so-called Portfolio Disks. These disks contain only low resolution images (512x768 and below) and are intended for creating catalogs and multimedia presentations. Picture Window grays out the high resolution menu items from a portfolio disk, to indicate that they are not present. The highest resolution, 4096x6144 will always be grayed out unless you have a professional format PhotoCD.

Certain high resolution images take a very long time to load

Images in a vertical (portrait) orientation take much longer to read in than horizonal (landscape) orientation unless you have enough RAM to store the entire image. For faster results, open the image in landscape orientation and rotate it afterwards using the Mirror/Rotate transformation .

Problems reading Corel Professional Photos CD-ROMs

The Corel series of image disks, while advertised as being in PhotoCD format, are created without an overview file. This overview file is what Picture Window reads to display a contact sheet of the images on the CD. To read images from one of these disks, you must use the File Open command and select the image type as Photo CD. Then select the desired image by its filename.

Problems reading 4096x6144 resolution images

An uncropped 4096x6144 image contains about 75MB of image data. Many computers do not have enough RAM or virtual memory to handle images of this size.


JPEG problems

Problems exchanging Picture Window JPEG files with other applications

If you are having a JPEG file compatibility problem please contact us.


Display problems

The display looks coarse

If your display adapter is set to 8-bit (256 color) mode, then Picture Window must use a technique called dithering to display color images. If possible, change the settings on your display adapter to 24-bit (16.7 million color) mode . This will also let you calibrate your monitor precisely. Picture Window also runs faster in this mode.

Display driver general protection faults

Even the latest Windows drivers for the various display cards occasionally cause general protection faults. This problem is unfortunately beyond our control. In the rush to market, manufacturers often release unstable drivers and then make updated versions available later. A good place to find these updated drivers are the web sites maintained by the various display card manufacturers. Links to many of these web sites can be found on the links page of our web site (www.dl-c.com). After downloading new drivers, follow the installation instructions included with the drivers.


File Open problems

Errors opening files

If you are trying to open a file that was created by a Macintosh system and downloaded from a bulletin board system, it is possible that the image file was exported in Mac Binary format. If so, you will need to strip the 128-byte header off of the file before you can read it using Picture Window. For more information on this, please contact our support department.


Printing problems

Dark bands running across images printed using the File Print command

We have seen this problem on systems with PrintCache (from Laser Tools) installed as a replacement for the Microsoft Print Manager. Switching back to Print Manager cures the problem.


Scanning problems

HP ScanJet scans are too light

The standard software included with the HP ScanJet assumes that you want to scan with a gamma of 1.8 which is the standard value used in the prepress industry. Picture Window uses a gamma of 2.2 however to match Photo CD, the video standard, and most PC monitors. The result is that images that look fine in the scanner preview window are too bright and the colors are off whenviewed in Picture Window. For more information about methods for fixing this problem, please contact Digital Light & Color.

"Image size not specified" error when scanning

This error message is reported when attempting to scan from certain scanners that do not specify the size of the final image in pixels before initiating a scan. Most scanners in this class are hand scanners or snapshot scanners. Picture Window does not provide direct support these scanners at this time. To use these scanners with Picture Window, you must first use the software that came with your scanner to scan the image and then transfer it to Picture Window either via the Windows clipboard or by saving it as a BMP file or in some other format that Picture Window can read and then opening it in Picture Window.


Fog filter

You can use Picture Window to create special effects that resemble a fog filter. The basic idea is to blend an image with a highly blurred version of itself. The simplest way to do this is to use the Blur transformation and select Gaussian as the method. Then select a large radius (such as 20 or 30) and reduce the amount to something like 50%. You can vary the effect by adjusting the radius and the amount.

Variations

You can create additional variations by accentuating the highlights of an image (with the Brightness Curve transformation), blurring them, possibly altering their color (with the Color Balance transformation), and then blending the result with the original (with the Composite transformation, possibly using the Lighten Only option).


How to use your photographs in documents and presentations

Using your photographs in word processing documents, brochures, and presentations is easy. There are two basic techniques -- using the Windows clipboard and saving and importing image files.

Working with the clipboard is simple but requires switching back and forth between programs first to copy and then to paste the images. If you already have saved image files, this can be cumbersome.

If you decide to transfer your images by importing files, you should be aware that the most widely supported image file format for Windows is the bitmap, or BMP format, so this is normally the best choice. Support for TIF and to a lesser degree PCX and TARGA files is also fairly common although may require the installation of a special import filter to allow your program to decode the information in the file.

Although copy and paste almost always works, the exact technique for importing and adjusting images does vary from program to program so we have included instructions for some of the most popular ones in the following sections. For more information or when using programs that are not listed below, please refer to the your manual or on-line help and search for "Graphics".

Microsoft Word

The easiest way to import a photograph into a Word document is the use the Insert Picture command. This requests you to enter the name of an image file to insert and then deletes the currently highlighted text and inserts the image at the current insertion point. Another way to achieve the same effect is to first copy the image to the Windows clipboard and then paste it into your document. To resize the image, click on it to select it and drag one of the corners. Images you import in this manner become part of the line of text into which they are inserted, and the height of the line is automatically increased to accomodate the height of the image.

To import a photograph so that text flows around the image, first activate page layout mode by executing the View Page Layout command. Then use the Insert Frame command and the click and drag the cursor on the screen to define the rectangular area in which you want the image to appear. This inserts a frame in the document around which the surrounding text will flow. Finally, insert the photograph in the frame using the Insert Picture command or by pasting an image from the clipboard. The frame and image can be resized by first clicking on the image to select it and then dragging one of the corners.

Word Perfect for Windows 6.0

To import an image, use the Graphics Drag to Create command. This lets you define where the image will appear by dragging the mouse. Next, click on the Image button on the tool bar and click and drag on the document to define the rectangle you want the image to occupy. When you release the mouse button, a dialog box pops up which lets you select the name of the file you want to insert. You can either select the file name directly or click the View button to pop up the file viewer which shows you a preview of each image as you select it.

Once you finish selecting an image, it will be inserted into your document and the Graphics Feature bar appears at the top of the screen. You can use these buttons to adjust various properties of the image. To reposition or resize the image, just click on it and drag its interior or one of its corners. To preserve the original proportions of the image, click on the Content button and check the Preserve Image Width/Height Ratio button. Normally, the text of the document is pushed aside by the image; you can adjust how text flows around the image by clicking the Wrap button. To add a caption to your image, click on the Caption button -- this pops up the Box Caption dialog box. To delete an image, just click on it to select it and press the Delete key.

PowerPoint

To import and image from the Windows clipboard, simply paste it into the desired slide. To import an image file, execute the Insert Picture command and enter or select the name of the file.

To reposition the image, first click on it to select it and then drag it to the desired location. To resize the image, click on it to select it and then drag one of its resize handles. To restore an image to its original size and proportions, double-click any of the resize handles.


Sepia toned prints

You can create an effect like that of a sepia toned print using the Monochrome and Tint transformations.

If you are starting with a color image, first convert it to black and white using the Monochrome transformation.

Next, you tint the black and white image with the Tint transformation. You can get a good approximation to a sepia toned print by adjusting the color line control to have three control points as follows:

This color line runs from a very dark brown at control point 1 through a richer brown at control point 2 to white at control point 3. You can experiment with different colors and different control point locations. When you get a setting you like, you can click the [image] button next to the color line and save it in a file for later reuse.

A file called SEPIA.CLN is included with Picture Window. Loading this file into a color line should give you a good starting point for creating sepia prints.


Extending the dynamic range of slide film

One of the biggest problems with slide film is its lack of exposure latitude. You can use the Composite Transformation to increase the dynamic range of slide film if you bracket your shots and have both a darker and a lighter version of the same image scanned in.

Given two different exposures of the same scene, the idea is to combine the highlights of one image with the shadows of the other. The trick is to align the two images precisely and then blend them the right way. The procedure is as follows:

Open both images; for reference we will call them image A and image B. Image A should be the lighter of the two images.

Select image A, click on the [image] icon to create a blending mask, and use the [image] tool to create a mask that is light (selected) where the image is light and dark (unselected) where the image is dark. A curve something like a straight line running from the lower left to the upper right corner should achieve this effect.

Leaving the mask in place, select Image A and bring up the Composite Transformation dialog.

Select Image B as the overlay image.

Select 2-point alignment.

Align image A and image B by locating two features in the image and positioning the alignment points on corresponding points of image A and image B. For best results, the alignment points should be as far apart as possible (such as opposite corners of the image). The alignment points must be positioned with very great accuracy; zoom both images in to at least 2:1 as you position the alignment points.

Experiment with the blending curve in the Mask dialog box and the Amount double slider in the Composite dialog box for the best results.

Click OK.


Getting Started

This section is a brief introduction to Picture Window for those who do not have access to the full Electronic Manual included with the CD-ROM version of the software.

Running Picture Window for the first time.

The first time you run Picture Window it will display a warning that your monitor has not yet been calibrated. To avoid seeing this message each time to run the program, select the File Calibrate command from the main menu. The full calibration procedure requires the use of a monitor calibration overlay which comes with the commercial versions of the Picture Window. To skip the calibration for, click the Reset button and then click OK and confirm that you want to save the calibration settings for future sessions. You can always go back and perform the calibration later.

The Screen

Picture Window divides the screen into several sections.

A standard Windows caption bar and main menu are at the top.

Below the menu is the tool bar ; you can hide the tool bar or make it run down the left side of the screen if you prefer (see the Window menu). To see what any of the icons on the tool bar do, simply position the mouse cursor over them briefly (without clicking) and a short description will pop up.

The remainder of the screen is the workspace which is like the surface of a giant light table. You can open images on the workspace and rearrange them at will. If one or more images extends beyond the currently visible part of the workspace, scroll bars automatically appear along its right and/or bottom edges to let you scroll other parts into view. You can change the color of the workspace background using the File Preferences command .

Image Windows

To open an image file in a window, use the File Open command. If your images are on a Photo CD , you can view them using the File Open PhotoCD command.

Once the file is open, the image is displayed in a window on the workspace. It is initially sized so that the entire image fits on the screen at once. The name of the file is displayed in the caption bar of the window; also displayed in the caption bar is the current zoom factor for the window (see below). Each image is surrounded by a border within its window. You can change the width and color of this border using the File Preferences command . Normally the border is white to help you judge the color balance and brightness of your images.

An image window is really just a view of the underlying image data; you can get a magnified view of the image by zooming in on a small area or a less detailed overview by zooming out. At a zoom factor of 1:1, each pixel in the image is displayed as one pixel on the screen. At magnified zoom factors like 2:1 or 3:1, each pixel in the image is displayed as a 2x2 or 3x3 block of pixels on the screen. At reduced zoom factors like 1:2 or 1:3, only every other or every third pixel is displayed. Zooming in or out magnifies or reduces the view of the image on the screen but never changes the underlying image stored in memory. See the Window menu for more information on the zoom in and zoom out commands.

When the entire image cannot fit in its window, scroll bars are displayed along its right and/or bottom edges to let you scroll other parts of the image into view.

To move an image window, simply drag its caption bar; to resize it, drag one of its corners or sides.

Transformations

Transformations are at the heart of Picture Window. Transformations take an input image, apply an operation to it, and produce a result image in a new window. Each transformation is controlled by a dialog box whose controls let you alter the its settings. When you are done, you will have two windows: the original, unmodified image and a new version of that image with the transformation applied to it. By comparing these side-by-side, you can see exactly what changes were made. To undo the operation, simply close the result window; to reclaim the memory used by the input image, you can close it. Or you can apply some different transformation to the input image to create a second result image that you can now compare to the other two. This method of operation differs from many other image editing programs that perform operations in-place, i.e. they replace the original image with the modified version and keep the original in an invisible undo buffer.

For more information on transformations, see Using Transformations .

Preview Windows

Most transformations have a Preview button; clicking this button creates a Preview Window which reflects what the transformation will do given its current settings. After creating the Preview Window, the Preview button remains grayed out until you change one or more transformation settings.

Initially, the preview window is relatively small so it can be updated quickly. However, you can resize the preview window by dragging its corners or sides, and you can zoom and scroll the preview window as well to see more detail in a specific region of the result image.

For those transformations that support the preview feature, there is also an Auto check box next to the preview button. When this box is checked, Picture Window automatically updates the Preview Window each time you change any of the transformation settings.

Freehand Tools

Unlike transformations, Picture Window’s freehand tools operate directly on an image and modify its contents. The Undo command can be used to reverse the effects of any tool, however.

Picture Window has tools for retouching images, lighten or darkening, removing red eye, removing dust specks and scratches, and more. For more information on the freehand tools, the Tools menu.

The general procedure for using tools is as follows:

1) Activate the tool by clicking its icon on the tool bar, via the Tools menu, or by clicking on its dialog box.

2) Adjust the settings in the tool dialog box.

The radius setting controls the size of the area the tool will affect. The larger the radius, the larger the area affected.

The transparency setting affects how strong the effect of the tool will be; the higher the transparency, the more subtle the effect. In most cases, a high transparency setting makes it easier to use the tools as you can gradually build up the effect you want.

The softness setting affects how abrupt the transition around the edges of where the tool is applied. The higher the softness, the more gradual the transition. In most cases, a high softness setting makes the effects of the tool more natural-looking.

The spacing setting affects how frequently the tool is applied as you pass it over the image; the smaller the spacing, the more times it is applied. In most cases, the default setting of 25% is a good choice.

3) To apply a tool to an image, click and drag it across the image. In the case of the Clone tool , you must first Shift-Click (hold either shift key down while clicking with the left mouse button) on the image to set the reference point.

4) If the results are not what you wanted, use the Undo command to reverse the effects of the last stroke. A convenient keyboard shortcut for Undo is Ctrl-Z. The File Preferences setting for Undo can be set to None, Single, or Multiple. In most cases a setting of Multiple is the most useful as it lets you undo each stroke you make, all the way back to when you first started using a particular tool.

Masks

When you want to apply a transformation just to part of an image, combine parts of one image with another, or protect part of an image from the effects of the freehand tools, you will need to create a mask. A mask is simply a black and white image with the same exact size in pixels as the image it is being used as a mask for. Additional information on creating and using masks can be found in other parts of this help file:

Creating Masks

Mask Dialog

Using Masks with Transformations

Using Masks with Tools

Masking Tips

Organizing your images

By default, when you open or save image files in Picture Window, it will start out in the same folder Picture Window was installed in. Rather than use this folder for your images, a better method is to create a new folder on your hard disk and, if you have a number of images, to organize these into subfolders of your main image folder.

You can change the default folder that Picture Window starts out with by changing the Startup Directory setting under File Preferences.


DLL Conflicts

The DLL Check command in the Help submenu examines your Windows and Windows\System folders for copies of the DLLs that Picture Window uses, and generates a report of any potential DLL conflicts it detects. These DLL conflicts can cause erratic behaviour or even system crashes when performing certain operations. Picture Window uses DLLs for two purposes: to read and write image files of various types, and to work with TWAIN drivers. If you are having trouble with either of these operations (especially reading or writing image files), it is worthwhile to check for possible DLL conflicts as these are one of the most common sources of problems in these areas.

What is a DLL conflict?

DLLs are Dynamic Link Libraries supplied by other companies as part of software we license from them. These libraries are then integrated with Picture Window to perform specific functions. For example, the DLL file: pcdlib32.dll comes from Kodak and makes it possible for Picture Window to read images from Photo CDs.

From time to time, new releases of these DLLs are issued to fix problems with older versions and/or to add new features. These new versions are typically installed when you install one of the programs that use them.

Ideally, all DLLs should be backward-compatible, i.e. a program that works correctly with an old version of a DLL should also work the same way with all newer versions. Also, in a ideal world, all installation programs would be careful never to replace a newer version of a DLL with an older version. As with other aspects of life however, all too often the real world falls short of the ideal world. When a program replaces a DLL installed by one program with a different version, the program that used the original version may stop working or exhibit erratic behaviour; this is called a DLL Conflict.

Where are DLLs installed?

DLLs can be installed in one of three locations on your computer:

1) in the same folder as the program that uses them

2) in the Windows folder

3) in the Windows\System folder

How does Windows locate DLLs?

When you run a program that uses a DLL, Windows first tries to find it in your Windows\System folder. If the DLL is there, this is the one it will use. If it’s not there, Windows searches for the DLL next in your Windows folder and finally in the folder containing the program. DLLs installed in your Windows or Windows\System folder are thus shared by all the applications on your computer; DLLs installed in a program’s folder are only used by that program.

If every program installed its DLLs in the program’s own folder, there would be far fewer DLL conflicts. Unfortunately, partly for convenience but sometimes out of necessity, programs install their DLLs in either your Windows or Windows\System folder where, due to the presence of different versions of the same DLL, conflicts can occur.

How does Picture Window install its DLLs?

When you install Picture Window, it copies all the DLLs it uses to your Windows folder, except for pcdlib32.dll which is copied to your Windows\System folder. If older versions of the DLLs are present, they are replaced.This may cause other programs to stop working. Newer DLLs are left in place by the installer, but, if they are not backward-compatible, they may cause Picture Window to malfunction. Copies of the same DLLs in your Windows\System folder can also cause problems as they will override any versions Picture Window installs in your Windows folder.

How to read the DLL report

When you execute the DLL Check command, Picture Window looks in your Windows and Windows\System folders for copies of the DLLs it uses. If it detects any potential conflicts, it generates a report in the form of a text file and prompts you for a location to save the file. You can then open and print this file using the Windows Notepad or Wordpad accessory or any word processor such as Microsoft Word.

For each DLL that poses a potential threat, Picture Window lists the following information:

1) The DLL name

2) The version number and file size in bytes of the DLL Picture Window would normally install

3) The location of the conflicting DLL.

4) The conflicting DLL’s version number and file size

How to resolve DLL conflicts

In examining the DLL report, if the version number of the conflicting DLL indicates that it is more recent than the Picture Window DLL, there is probably not a problem (unless the DLL has not been poorly written and is not backward-compatible). If the version number of the conflicting DLL indicates that it predates the Picture Window DLL, then some application has probably rudely installed an out-of-date DLL in place of the newer version Picture Window had previously installed or has installed the older DLL in your Windows\System folder where it overrides the one Picture Window installed. In this case, the problem can probably be eliminated by deleting the DLL and reinstalling Picture Window.

If the simple approach does not work, the definitive way to resolve nasty DLL conflicts fully is to move each conflicting DLL into the same folder as the program that installed it. This allows each program to use the DLL it installed and was tested with. Unfortunately, it is not always easy to determine which programs installed which DLLs without painstakingly removing and reinstalling each application.

By default the Picture Window folder is located in:

C:\Program Files\Digital Light & Color\Picture Window 2.5

or, for Picture Window Pro, in

C:\Program Files\Digital Light & Color\Picture Window Pro 2.5

What DLLs does Picture Window use and what does each one do?

A complete list of the DLLs Picture Window uses is given below: Picture Window normally installs all of these DLLs in your Windows folder.

DLL	What function it performs

lfbmp10n.dll	BMP file support
lfcmp10n.dll	JPEG file support
lfeps10n.dll	EPS file support
lffax10n.dll	TIFF file support
lffpx10n.dll	FlashPix file support
lffpx7.dll	FlashPix file support
lfgif10n.dll	GIF file support
lfkodak.dll	FlashPix file support
lfpcd10n.dll	Photo CD file support
lfpcx10n.dll	PCX file support
lfpng10n.dll	PNG file support
lftga10n.dll	Targa file support
lftif10n.dll	TIFF file support
ltfil10n.dll	Used by all file types
ltkrn10n.dll	Used by all file types
ltwrp10n.dll	Used by all file types

pcdlib32.dll	Photo CD support

twain.dll	TWAIN support
twain_32.dll	TWAIN support

NOTE: For the Digital Light & Color screen saver to work, all but the TWAIN DLLs must be present in your Windows folder. If you move these files to the Picture Window folder, Picture Window will still work, but the screen saver will not. The TWAIN DLLs must be located in your Windows folder. If you move them, you may not be able to use any of your TWAIN drivers.


Working with 16-bit black and white and 48-bit color images

Note: 16-bit black and white images and 48-bit color images as described below are supported only by the Pro version of Picture Window.

What are 16-bit images?

In a normal black and white image, each pixel is represented by a single byte (8 bits) of image data. This allows for 256 distinct brightness levels running from pure black to pure white. The human eye, even under the best conditions, can barely distinguish 200 gray levels, so for most purposes 8 bits are adequate. Similarly a color image is made up of three components (red, green, and blue) and each of these is again represented by an 8 bit value. Taking all possible combinations, this leads to about 16.8 million possible colors.

In a 16-bit black and white image, each pixel is represented by two bytes (16 bits) of image data. This increases the number of possible gray levels from 256 to 65,536. A 48-bit color image is made up of three 16-bit values, one each for red, green, and blue.

Why use 16-bit images?

The main reason for using 16-bit images is that they provide a much finer gradation of brightness levels and this, in turn, lets you significantly alter an image’s brightness and dynamic range of an image while retaining a full, smooth range of tonal values in the final result.

Normally, when you scan an image using a 30-bit or 36-bit scanner, the extra bit depth in the image is used internally by the scanner hardware or software when making adjustments to the image. The adjusted image is then reduced to 24 bits and passed to your computer. However, if you have a 30-bit or 36-bit scanner that can tranmit this extended range of information to your computer (more on this below), you have more options. You can scan the image with no adjustments and then use Picture Window Pro with its more powerful and precise tools, masking capabilities, and retouching tools to get the best possible image instead of relying on the software that comes with the scanner.

For certain specialized compositing applications, the additional bits also provide the greater numerical range needed to combine images with the greatest possible accuracy.

How to get 16-bit images

There are two ways to get 16-bit images into Picture Window:

Scanning

Some new flatbed and film scanners can capture 30, 36, or even more bits per pixel and are capable of transmitting this information, via their TWAIN driver, to your computer. The image data is automatically scaled to produce a full range 16-bit black and white or 48-bit color image when it is transferred. For Picture Window to be able to produce a 16-bit image, both the scanner and its TWAIN driver must support this feature. Typically, a TWAIN driver will refer to 16-bit image as something like “Billions of Colors”, “48-bit Color”, “10-bits”, or “12 bits”. A number or 30-bit and 36-bit scanners, while they can capture extended data, their TWAIN drivers do not support transmitting this data to the computer.

Passing all the image data from your scanner to Picture Window Pro lets you use Picture Window Pro’s more powerful image enhancement functions instead of those in the scanning software.

File Open and Save

Only a few of the image file formats currently in use support 16-bit images. The most popular of these if TIFF, but Picture Window Pro can also open and save 16-bit black and white images in FITS format (used primarily by the scientific community). Consequently, when you save a 16-bit black and white image, your only file type options are TIFF and FITS; for 48-bit color the only option is TIFF.

Converting between 16-bit and 8-bit images

You can convert between 8-bit and 16-bit images at any time using the Convert transformation. This lets you perform a series of operations using high precision 16-bit images and then, at the end of the process, convert the final result to 8 bits for archiving or export.

Using 16-bit images

Once you have a 16-bit black and white or 48-bit color image, you can use any of Picture Window’s commands, transformations or tools to work with it. The one restriction is that you cannot use a 16-bit black and white image as a mask. Of course you can convert it to 8 bits and then use it as a mask.

To check on the type of image in a window, you can use the Window/Info command. The image type is displayed at the top of the dialog box; 8-bit black and white and 24-bit color are called “Black and White” and “Color”; 16-bit black and white and 48-bit color are called “16-bit Black and White” and “48-bit Color”.

For faster operation when using transformations, the Preview feature generally works by treating input images as 8-bit. This means that in some cases, like a radical change in brightness or color, the preview image may look posterized. When computing the final image however, the full 16 bits are always used.

When using transformations like Brightness Curve which display histograms of the input image, these histograms are only computed using 256 levels since the full 65,536 levels would be too many to display on the screen at once. Again, the final curves are computed based on the full 16-bit data.

Note that 16-bit black and white and 48-bit color images use twice the memory of their 8-bit and 24-bit counterparts, so you may want to get more RAM if you routinely work with 16-bit images. In addition, a number of the processing techniques used by Picture Window Pro take more time when used on these larger image.