Copyright: Copyright ©1996 Rhode Island Soft Systems, Inc.


Contents
Welcome to Palette Express!

Digital artists have been struggling with "Palette Clash" for years -- the unsightly effects of trying to simultaneously display images that use radically different color palettes.   Now there's a simple, effective way to manage digital art -- Palette Express!   Developed by the authors of the Ovation Studio Pro Suite of Multimedia Development Tools, Palette Express is a dream come true for anyone who has to deal with digital artwork including Web developers, Multimedia Developers, and Digital and Graphic Artists.

Please click on the topics below in order to learn more about using Palette Express to manage color palettes, convert among popular file formats, and more.

Overview

Input Tab

Output Tab

Palette Tab

Transparency Tab

Common Uses for Palette Express

Registering Palette Express

About Rhode Island Soft Systems, Inc.

Palette Express is not free, it is shareware.  You are encouraged to try Palette Express for a reasonable period (60 days maximum).  If you find Palette Express to be useful, you must register your copy of the software.   Besides fulfilling a legal obligation, you will also receive a copy of the full registered version of Palette Express (with support for unlimited # of images, JPEG support, add'l file import/export filter support, and both 16 bit and 32 bit versions of the software), as well as access to updates, technical support, and special offers.

Palette Express is a trademark of Rhode Island Soft Systems, Inc.

Copyright (c) 1996 Rhode Island Soft Systems, Inc.  All rights reserved.


Input Tab

Input options determine which image files will be processed.

File Name(s)

This field and its list box specify the image files to be processed. Multiple files can be selected or typed in the edit control. File names should be separated by spaces.

Holding the Control key and clicking the left mouse button on a file name turns its selection on or off. Holding the Shift key and clicking the left mouse button on a file name selects all files from the current selection to the clicked file. Holding the left mouse button and dragging through the list box also selects a range of files.

For keyboard interface, you can tab to the list box and select files by pressing the up or down arrows. Hold the Shift key to select multiple files.

Alternatively, you can use a search string to match files. A * in a file name matches any sequence of characters and a ? matches a single character. For example, type G*.BMP to process all bitmap files that begin with the letter G.

File Type

This field determines which types of files are listed in the File Name(s) list box. Note that typing a new search mask in the File Name(s) field also changes the list of files.

This field is also used in conjunction with the Process All Files of Type switch. When that switch is checked, all files with the extension specified in this field are converted.

Process All Files of Type

This field specifies that all files with the extension specified in the File Type field are to be processed. Selecting this option disables the File Name(s) field.

Search Directories

This field specifies that all sub directories from the selected are to be searched for files to process. If a search string is specified in the File Name(s) field, that search string is applied to all directories searched.

When this option is selected, Palette Express creates the same sub directories below the output directory.

Directories

This field specifies the directory from which files are to be processed. Changing the directory changes the list of available files in the File Name(s) field.

When the Search Directories switch is checked, Palette Express will look for files in the selected directory and all directories below it.

Double click on a directory name to change to that directory. The double dot [..] in the directory list means "go up one level".

For keyboard interface, tab to the directory field and use the up and down arrow keys to change the directory selection. Then press Enter to change the directory.

Drives

This field specifies the disk drive from which image files are to be processed. Changing the drive changes the list of directories and file names.


Overview

(See also: Common Uses for Palette Express)

Palette Express is an invaluable tool for multimedia and internet developers. Its primary function is to reduce a group of images to an common palette of colors, either optimized or selected, but it can also be used to convert image file formats. Palette Express is flexible enough to suit many needs. It has different options to control the palette selection and the image file reduction and conversion.

Development of artwork for multimedia applications is typically done in true color (24 bits per pixel). However, since many computers only support 256 colors (8 bits per pixel), images must be reduced before an application can be distributed to the general public. Most software that reduce images will either apply an existing palette or produce a different palette for each image. This is undesirable because an existing palette may not be best suited to all of the images and different palettes will cause serious color loss when the images are displayed concurrently. Palette Express addresses these issues by first analyzing all of the images and building an optimal color table and then reducing all of the images to the new palette.

Internet developers face another issue. Most Web browsers use a specific color palette and reduce images on the fly as they are received. Typically the reduction methods used sacrifice quality for speed. Palette Express gives you the ability to reduce images to a specific palette in advance so they are already optimized for display in a particular browser. In fact, Palette Express comes with many of the common browser palettes so you can choose which palette to apply to your images.

Similar to the Web browser issue, multimedia applications that use full motion video need to reduce their images to match the video driver's palette. Otherwise, palette flash (brief distortion of colors on the screen when a new color palette is selected) and degradation in image quality can result. As with browser palettes, Palette Express comes with many of the common video palettes so you can reduce your images to match the video driver's palette.

Palette Express supports the following file formats.

BMP	Windows bitmap.

BMP RLE4	Windows compressed bitmap.

BMP RLE8	Windows compressed bitmap.

GIF	Compuserve.

JPG	JPEG (JFIF Compliant)

RGB	Ovation Studio Pro palette.

PAL	Paint Shop Pro palette.

PAL	Microsoft Palette.

In addition, any other image file formats supported by Graphics File Extension Format (GFEF) filter modules* are automatically supported by Palette Express.

* GFEF filters are add-on modules that provide a means by which applications can support additional file formats. GFEF modules are installed separately and can be obtained from Rhode Island Soft Systems, Inc. or from any other developer of GFEF modules. Note that Rhode Island Soft Systems, Inc. does not provide support for third-party modules. The JPEG support included with Palette Express is provided by a GFEF module.

Palette Express supports the following color depths for input.

2 color (1 bit)

16 color (4 bit)

256 color (8 bit)

256 gray scale (8 bit)

16 million color (24 bit)

Palette Express provides the following color depths for output.

2 color (monochrome)

16 color with or without Windows colors

256 color with or without Windows colors

256 gray scale

16 million color (TrueColor)

Palette Express provides the following reduction methods.

Nearest Color

Error Diffusion

Usage

The Palette Express interface consists of a dialog with four tabs for choosing input, output, palette, and transparency options. A typical session involves selecting files to be processed, choosing a reduction method and destination for converted files and choosing palette selection or creation options. When your options are selected, press the Go button to begin processing.

Palette Express displays a progress box with information about the files it is processing. During processing, you can pause, resume and cancel. If errors occur, Palette Express will display a log window describing each error. Unless an error prevents continuation, for example a selected palette cannot loaded, Palette Express will ignore the file in error and continue processing.


Output Tab

Output options determine reduction method, file conversion and destination.

Convert Files

This switch enables image file conversion. Turning this switch off enables you to use Palette Express to simply create a palette file.

Note that if this switch and the Save Palette As switch (on the Palette tab) are both turned off, then Palette Express will display a message indicating that there is nothing to do.

Confirm Overwrites

This switch tells Palette Express whether to ask before overwriting an existing file. When this switch is checked, Palette Express will display a confirmation box with the following options when an existing file is encountered.

Replace	Replace the specified file and continue.

Replace All	Replace the specified file and all other files without asking again.

Skip	Skip the specified file and continue.

Skip All	Skip the specified file and all other files without asking again.

Cancel	Cancel all processing. Palette Express will ask for confirmation of this option.

If this switch is not checked, Palette Express will overwrite all existing files without asking.

Output Type

This field specifies the format to which image files are to be converted. Note that some formats such as JPEG do not support all color depths and therefore choosing those formats will disable some color options on the Palette tab.

Output Format

This field specifies the format to which image files are to be converted. Formats available depend on the selected Output Type. Note that some formats such as RLE do not support all color depths and therefore choosing those formats will disable some color options on the Palette tab.

Extended Parameters

Some file types support additional parameters to control how the image file is created. For example, JPEG provides options to control the quality and speed of compression. This button is enabled only when extended parameters are supported by the selected Output Type.

Dither Method

This field specifies the dithering method to use when applying the new palette to images. The following methods are available.

Nearest Color	Each pixel in the source image is mapped to the nearest color in the new palette. This method usually runs faster than the Error Diffusion method but generally produces lower quality color reduction.

Error Diffusion	Pixels are mapped to the nearest color, but an additional correction is performed by propagating a fraction of the difference between the original and new pixels to the next pixel in the image. This method usually produces better color reduction but can run a little slower than the Nearest Color method.

Directories

This field specifies the directory to which converted image files are to be written. When the Search Directories field on the Input tab is checked, Palette Express will create any sub directories from the input directory below the selected output directory.

Note that input and output directories cannot be the same. Palette Express will display an error message if the same directory is chosen for both input and output.

Double click on a directory name to change to that directory. The double dot [..] in the directory list means "go up one level".

For keyboard interface, tab to the directory field and use the up and down arrow keys to change the directory selection. Then press Enter to change the directory.

Drives

This field specifies the disk drive to which converted image files are to be written. Changing the drive changes the list of directories.


Palette Tab

Palette options determine palette selection or creation.

Retain Image Colors

Selecting this option tells Palette Express to retain the image's original color format whenever possible. If a color reduction or expansion is required for translation to the specified output format, then Palette Express will perform the color depth change automatically.

Load Palette

Selecting this field tells Palette Express to load a palette from the specified file and apply it to all selected image files. A valid file must be specified. Click on the browse button to browse for a palette file.

Note that a palette can also be loaded from an image file.

Create Optimized Palette

Selecting this field tells Palette Express to create an optimized palette based on the image files it processes. The following options are available.

2 Color	This option reduces images to monochrome (1-bit).

16 Color	This option generates a 16 color palette. If the Include Windows Colors switch is checked, the standard Windows 16 color palette is used. Otherwise, an optimized 16 color palette is created.

256 Color	This option generates a 256 color optimized paletted. If the Include Windows Color switch is checked, the standard 16 Windows colors are included in the palette.

Gray Scale	This option generates a 256 gray scale palette. Windows colors cannot be included in a gray scale palette.

True Color	This option increases the color depth for all images to 16 million (24-bit). 24-bit images do not have a palette.

Include Windows Colors	Checking this switch includes the standard 16 Windows colors in the color palette.

Note that when Windows colors are included in a palette, Palette Express always creates an identity palette. An identity palette has the Windows colors arranged at the beginning and end of the palette. This matches the Windows run time arrangement and therefore makes image display faster.

Optimize Per Image	Checking this switch tells Palette Express to create an optimized palette for each image. Normally, Palette Express creates a single palette that is optimized for all selected images. When this switch is checked, Palette Express creates a new optimized palette for each image.

Note that when this option is checked, the Save Palette As option is disabled because multiple palettes are created.

Note that some options may be disabled depending on the output format chosen in the Output Type field on the Output tab.

Save Palette As

Selecting this field tells Palette Express to save the palette it creates to a palette file. A valid palette file name must be entered or click the Browse button to choose a directory and file name.

Palette Express determines the palette file format from the file name extension. For example, if the file name ends with .RGB, Palette Express creates an Ovation Studio Pro palette file. If the file extension is not recognized, Palette Express defaults to the Ovation Studio Pro palette file format.

The file extension PAL is used for both Paint Shop Pro and Microsoft palette files. When a file name with this extension is given, Palette Express cannot know which format to use. The PAL File Format option allows you to choose which PAL file format to use. The following options are available.

Paint Shop Pro	Save palette in Paint Shop Pro palette file format.

Microsoft	Save palette in Microsoft palette file format.


About Rhode Island Soft Systems, Inc.

Rhode Island Soft Systems, Inc. is a developer of consumer and business software products including games, utilities, and multimedia development tools.  For more information the entire line of products, please contact the company in any one of the following ways:

Rhode Island Soft Systems, Inc.

P.O. Box 748

Woonsocket, RI 02895-0784

Phone: 401-767-3106

Internet:  http://www.risoftsystems.com

email:  sales@risoftsystems.com

CIS:  GO RISS, Lib/Sec 5

BBS:  401-767-3931

Fax:  401-767-3108


Common Uses for Palette Express

This section describes how to perform a few of the more common tasks with Palette Express.

How to Reduce Image Files to an Optimized Palette

1. Choose the image files to be processed on the Input tab.

2. Choose the destination for converted images on the Output tab.

3. Choose the Create Optimized Palette option on the Palette tab and then choose the palette options (256 color, Include Windows Colors, etc.).

4. Choose transparency options (if needed) on the Transparency tab.

How to Reduce Image Files to a Specific Palette

1. Choose the image files to be processed on the Input tab.

2. Choose the destination for converted images on the Output tab.

3. Choose the Load Palette option on the Palette tab and enter a valid palette or image file in the edit field.

4. Choose transparency options (if needed) on the Transparency tab.

How to Reduce Image Files to Individually Optimized Palettes

1. Choose the image files to be processed on the Input tab.

2. Choose the destination for converted images on the Output tab.

3. Choose the Create Optimized Palette option on the Palette tab and then choose the palette options (256 color, Include Windows Colors, etc.).

4. Check the Optimize Per Image switch on the Palette tab.

5. Choose transparency options (if needed) on the Transparency tab.

How to Create and Save a Palette Without Converting Image Files

1. Choose the image files to be processed on the Input tab.

2. Turn off the Convert Files switch on the Output tab.

3. Choose the Create Optimized Palette option on the Palette tab and then choose the palette options (256 color, Include Windows Colors, etc.).

4. Turn off the Optimize Per Image switch on the Palette tab (this switch must be turned off).

5. Turn on the Save Palette As switch on the Palette tab and enter a valid palette file name.


Registering Palette Express

Palette Express is not free, it is shareware.  You are encouraged to try Palette Express for a reasonable period (60 days maximum).  If you find Palette Express to be useful, you must register your copy of the software.  Besides fulfilling a legal obligation, you will also receive a copy of the full registered version of Palette Express (with support for unlimited # of images, JPEG support, add'l file import/export filter support, and both 16 bit and 32 bit versions of the software), as well as access to technical support, updates, and special offers.

To register Palette Express, either call 1-800-959-RISS   or fill out the following form and mail, fax, or email it to Rhode Island Soft Systems, Inc. along with your payment.

Announcing Electronic Delivery!   You may choose whether you would prefer the software mailed to you on diskette, or emailed (as a roughly 550K .ZIP file) to your internet account.  Electronic delivery is cheaper (save the $5 S&H) and significantly faster -- often a same-day turnaround.  If you are not accustomed to receiving binary files via email (typically a MIME-encoded .ZIP file),

you will probably want to opt for standard delivery.

Rhode Island Soft Systems, Inc.

P.O. Box 748

Woonsocket, RI  02895-0784

U.S.A.

FAX: 401-767-3108

email:  71231.2614@compuserve.com

Credit Card Orders:	1-800-959-7477

   or  	1-401-767-3106

[  ]	I would like to register Palette Express and receive the full registered version.

Please send _____ registered copies of  Palette Express for only  $39.00 (U.S.) each.

(volume discounts for more than 10 copies are available -- please call for details)

----------------------------------------------------------------------------------------------------

1)  Subtotal for Palette Express  (# of copies X $39.00)	$________

2) Choose a delivery option:

    Electronic delivery to this email account:_____________________	$__FREE!_

     or

    U.S. Mail to U.S. or Canada, add $5  S&H	$________

     or

    Delivery outside U.S. or Canada, add $10  S&H	$________

 	Amount Enclosed    	$________

[ ]  I have enclosed a check (in U.S. Funds to R.I. Soft Systems, Inc.)

     or

[ ]  Please charge my:	[ ] Visa	[ ] Mastercard	[ ] AmEx	[ ] Discover

     Signature:______________________________

     Card Number:___________________________ Expiry Date:______________________

My name and mailing address is:

    Name: ________________________________________________________________

    Street/PO Box: __________________________________________________________

    City: ____________________  State: _______  Zip Code: ________________________

    Phone Number: __________________   Fax Number: ____________________________

    Email address: _________________________________

How did you hear about Palette Express? _________________________________________

_________________________________________________________________________

_________________________________________________________________________


Transparency Tab
Transparency Options

Transparency options specify how Palette Express should handle transparent colors when converting between file formats and applying palettes. Transparency is normally implemented by reserving one color as the transparent color. When the image is rendered, the background shows through wherever that color is present.

Palette Express provides transparency options for two reasons. First, when performing color reduction, color values are approximated and, with some methods, an error term is propagated to surrounding pixels. Since there can only be one transparent color, this approximation can cause a halo effect around an image or even wipe out the transparency entirely. Second, since some file formats do not explicitly define transparency, Palette Express needs to know how to determine the transparent color in a particular image.

The transparency options provided by Palette Express resolve the two aforementioned issues.

Input Transparent Color

These options tell Palette Express how to determine the transparent color in images whose format does not specify one. Note that these settings are ignored when the input image format, such as GIF 89a, supports transparency.

None	This option tells Palette Express not to treat images as transparent unless their format explicitly specifies transparency.

RGB	This option tells Palette Express to use the color specified by the red, green and blue components (entered at the right of this option) as the transparent color.

Color Index	This option tells Palette Express to use the color table index (entered at the right of this option) as the transparent color. The index specified for this option refers to a color in the image's color table. Therefore, it is assumed that all images being processed have the same color table or at least a transparent color in the same position.

Note: Since true color images do not have a color table, they will be treated as non-transparent when this option is selected.

Also note that if the color index specified is out of range for a particular image, that image will be treated as non-transparent.

First Pixel	Choose this option to have Palette Express use the first pixel (upper left corner) of each image it processes as the transparent color.

Output Transparent Image When

These options tell Palette Express when to write images as transparent. Besides telling Palette Express to use the transparency feature in file formats that support it (such as GIF 89a), these options also affect how the dithering process is applied.

Input File Is Transparent	This option tells Palette Express to create a transparent image only when the input image is determined to be transparent. When the input format does not support transparency, the Input Transparent Color setting is used to determine transparency.

Always	This option specifies that all files are to be output as transparent.

Never	This option specifies that no files will be output as transparent.

If the output file format supports transparency, Palette Express will use it whenever appropriate. If the output file format does not support transparency, Palette Express simply maintains a unique color for transparency.

When images determined to be transparent are dithered, the transparent color is maintained and kept unique throughout the dithering process. Also note that the transparent color for a particular image may change when multiple images are processed and when the color depth for an image is reduced.