HyperLib 1997 Winter - Disc 1/HYPERLIB-1997-Winter-CD1.ISO.7z/HYPERLIB-1997-Winter-CD1.ISO/第１特集Plug-in/Photoshop/PhotoLabDemo.sit/PhotoLabDemo/PhotoLab Demo filters/PhotoLab Demo User Guide.txt

Text File | 1995-08-16 | 12KB | 94 lines

CSI PhotoLab Demo Filters User Guide.

CSI PhotoLab filters provide the most efficient and precise way to color correct your image based on traditional photographic principles. The complete version of CSI PhotoLab consists of eight filters designed for use by professional photographers and prepress professionals. These filters are designed to bring out the maximum potential in your image by controlling and manipulating exposure, contrast and color casts. Included in the complete package are powerful controls for color negative inversal and special effects such as accurate Sepia tones, infrared simulations and flexible noise generation.

What are the PhotoLab Demo Filters?
We have included three out of eight filters. Each filter will run for 5 tries only.
･ﾊCSI GradTone.
A quick way to colorize an image based on itﾕs luminance values.
･ﾊCSI Negative.
Accurately convert black and white and color negatives to positives by stripping off the color cast and tonal compression.
･ﾊCSI PhotoFilter.
Computes the effect of traditional glass or gel filters in front of the cameraﾕs lens. Apply familiar and consistent color correction using presets such as CC10 etc.

What are the rest of the PhotoLab filters?
･ﾊCSI HueSlider.
Crucial for collaging. Change the color cast of one image to match another image.
･ CSI Levels.
Manipulate exposure and tonal contrast using an interface designed for Photographers. Produce optical sharpening for high-qualiity professional results.
･ﾊCSI MonoChrome.
Produce monochromatic images with greater control over color, contrast and exposure than Photoshop's Duotone feature.
･ CSI Noise.
Color and brightness noise to simulate film grain, reticulation and fine art effects.
･ﾊCSI PseudoColor
Produce color infrared simulations and stylized pop-art effects.

Common Features:
All of the PhotoLab filters feature a common interface to using tools and buttons. This makes navigating in the filter dialog more intuitive. Here are some of the tools you will be using.

Dynamic Previews:
At the top of each PhotoLab filter are ﾔbeforeﾕ and ﾔafterﾕ previews. The first preview on the left is a thumbnail of the original image. This thumbnail does not change. The second preview on the right is dynamic, and allows you to see the changes you specify in real-time.

On-Line Help:
All of the filters have a help button located at the bottom-right of the filter dialog. The help screen highlights the functions of each button or icon in the filter. Click the Finished button to return to the filter dialog.

Reset, Cancel and OK:
All PhotoLab filters have three buttons labelled Reset, Cancel and OK. Clicking on the OK button causes the filter to apply the current settings to the image, or selected areas of the image. Clicking on the Cancel button closes the filterﾕs dialog without any changes to the image. Clicking on the Reset button sets all the controls in that filter to their default positions. PhotoLab filters remember the last settings used when the filter was closed either by clicking on the Cancel or OK buttons.

Color Selection:
There are generally at least two ways to choose color in most of the filters. The primary method is by using the actual color correction presets as in the case of CSI PhotoFilter. The second method is by using the eyedropper button in the appropriate filters. To use the eyedropper click the button first to engage color sampling. This causes the eyedropper button to reverse out. Move the eyedropper cursor on top of the desired color and click again. This sets the sampled color to be the current color in the swatch. The eyedropper will sample colors from the image, the Macintosh Desktop or other swatches open in the background. In short, it will sample any color that you are able to move the cursor on top of. The third way to select color is by clicking on the color swatch, or swatches that most of the filters have. Clicking on the color swatch displays the System color picker. You can then choose the desired color.

RGB or CMYK?
Although PhotoLab filters can be used with either RGB or CMYK images, we have found that best results are obtained by processing and photo-retouching RGB images, and later converting to CMYK to produce CMYK prints or color separations.

Presets:
Each filter has its own set of default settings or presets which you can customize further. The default settings controls consist of three buttons and a popup menu. The popup menu is used to select a previously saved or supplied setting. The buttons are Save, New and Delete. The Delete button is inactive or gray in color if no named preset has been selected.


CSI GradTone.

The CSI GradTone filter is analogous to using a split field or graduated chromatic filter on your camera lens. These traditional filters have color spread over only half of their field, or in differing densities over the entire surface. CSI GradToneﾕs functionality extends well beyond this. Use GradTone to selectively infuse parts of the image with a color, quickly colorize an image using any number of colors, reproduce chemically-correct sepia tone reproductions and other effects.

How does it work?
This filter is used to replace or add to the existing colors of an image based on the luminance of the image. The filter first computes the grayscale equivalent of each pixel in the image and then either replaces the pixelﾕs components with new colors or applies the new colors in a transparent fashion. CSI GradTone preserves the tonal integrity of the image. In other words, color changes that are introduced do not change the appearance of the original image in terms of density. Only the color values change. This is especially important when creating effects such as sepia, where it is important to preserve detail in the original while the colors change.

Once a color has been selected, you need to apply that color to the black Gradient Scale. The bar represents the total tonal range of the image ranging from 0 to 255. We have added a static grayscale reference bar beneath the Gradient Scale. Placing a color at any point along the Gradient Scale will have an effect on the pixels in the image that correspond to that position.

The transparency or opacity button when clicked allows the filter to either replace the affected pixels with the colors on the black bar, or to apply the colors on the black bar in a transparent fashion.

The Reverse Scale button switches the colors on the Gradient Scale from left to right and right to left. Clicking on this button causes low luminance settings to become high luminance settings and the reverse.

The magnifying glass button above the eyedropper is called the Density Scale. This may be used to examine the Gradient Scale to know the grayscale equivalency of a certain color on the bar. The Density Scale mode stays on as long as the mouse button is held down over the bar.


CSI Negative.

The CSI Negative filter is used to convert a negative film scan into a positive image. CSI Negative has great value as a production tool for accurate conversion of negative film into positive by removing the orange cast in the base of the film stock; as well as for converting final color images into negatives for output where required.

The properties of a negative film image are not just the inverse of a positive image. If that were true then simply inverting the colors would suffice. The chemical process that creates color negative film also logarithmically compresses the inverted data and matches the inverted colors to that of the acetate carrier material which generally has an orange tint. The Negative filter addresses this tonal compression, removes the orange cast and inverts the image data.

 To convert a scanned color negative into a positive image, click on the Reversal film check box. This enables color correction and tonal decompression. If this option is left unchecked, only color inversion with shadow, highlight and exposure compensation is performed.

Additional controls let you adjust the shadow, highlight and exposure controls to compensate for negatives taken under varying light conditions. Adjusting the highlight, shadow and exposure controls alter contrast along perceptual lines. When altering the tonal contrast in an image, highlight and shadow controls are able to stretch the tonal range between -50% to 150%, expanded from the normal range of 0 to 100%. This creates a temporarily expanded color space for tonal corrections. After you have made your changes, this expanded color space is compressed more smoothly into the 0 to 255 range of levels. This technique helps to preserve tonal relationships and produces smooth ramps and an even distribution of tones. This is especially critical when fine work is required such as working with skin tones. Use the Exposure Control field to further enhance the smooth quality of the image.

The Equalize button allows balancing the effects of shadow and highlight settings to produce a more pleasing effect.

Scanning
When scanning in negatives, set the scanning software to produce an uncorrected color non-inverted image.


CSI PhotoFilter.

CSI PhotoFilter is used to modify the color cast of a complete image. Besides changing the color cast, CSI PhotoFilter can also change or correct the exposure of the image.

CSI PhotoFilter uses a sophisticated optical color matching method that computes the effect of placing a traditional glass or gelatine filter in front of a cameraﾕs lens. For example, if you decided to add red to the image, the green and blue hues will be affected too, although inversely. Optically, adding red is the same as subtracting green and blue. To ensure correct tonal balance, CSI PhotoFilter adds the red and subtracts the green and blue in percentages that preserves the overall tonal quality of the image. CSI PhotoFilter simulates the effect of filters and is not the same as using color editing tools such as curves or levels in image editing programs. Red has been used as an example but the method applies to any selected color.

Experiment with the various presets provided to see the effects of the various lens filters provided. When using PhotoFilter presets, especially the color correction and light balancing settings, keep in mind that PhotoFilter will automatically shift the exposure to compensate for the filter factor. This is similar to  using a real filter on a non-auto-exposure camera. In this case it is necessary to increase the exposure to compensate for the loss of light resulting from using the filter.


Configuration.

Although CSI PhotoLab will operate on any Macintosh model with at least a 68020 processor it is absolutely necessary for Macintosh System 7 or greater to be used as the operating system. PhotoLab uses certain features of System 7 and will not operate correctly under System 6 or earlier. PhotoLab is fully compatible with PowerPC Macintoshes and with System 7.5. For best results we suggest using a computer with a 68040 processor or a PowerPC based Macintosh.
It is strongly recommended that at least 1 or 2 megabyte of free memory be available to the operating system after setting the Preference Size for your application, and in addition to what the operating system uses normally. If your application requires more memory than is currently available, you may either increase the amount of memory by using Virtual Memory, accessed through the Memory Control Panel, or increase the amount of physical memory (RAM). Using Virtual Memory will allow your application to run, but you may experience much slower response times when using PhotoLab filters.
PhotoLab is completely compatible with virtual memory systems, but to obtain the fastest possible results it is always better to have sufficient physical memory (RAM).