Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 404

AFTER EFFECTS CS3 398
User Guide
The flexibility of the color-matching operation. 0% decolors all pixels except those that exactly match
Tolerance
Color To Leave. 100% causes no color change.
The softness of the color boundaries. High values smooth the transition from color to gray.
Edge Softness
Determines whether colors' RGB values or HSB values are compared. Choose Using RGB to perform
Match Colors
more strict matching that usually decolors more of the image. For example, to leave dark blue, light blue, and
medium blue, choose Using HSB and choose any shade of blue as Color To Leave.
Levels effect
The Levels effect remaps the range of input color levels onto a new range of output color levels, with a distribution
of color values determined by the gamma value. This effect functions much the same as the Levels adjustment in
Photoshop.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
Original (left), and with effect applied (right)
The color channels to be modified.
Channel
Shows number of pixels with each luminance value in an image.
Histogram
Pixels in the input image with a luminance value equal to the Input Black value are
Input Black and Output Black
given the Output Black value as their new luminance value. The Input Black value is represented by the upper left
triangle below the histogram. The Output Black value is represented by the lower left triangle below the histogram.
Pixels in the input image with a luminance value equal to the Input White value are
Input White and Output White
given the Output White value as their new luminance value. The Input White value is represented by the upper right
triangle below the histogram. The Output White value is represented by the lower right triangle below the histogram.
The exponent of the power curve that determines the distribution of luminance values in the output image.
Gamma
The Gamma value is represented by the middle triangle below the histogram.
These controls determine the results for pixels with luminance values
Clip To Output Black and Clip To Output White
that are less than the Input Black value or greater than the Input White value. If clipping is on, pixels with luminance
values less than the Input Black value are mapped to the Output Black value; pixels with luminance values above the
Input White value are mapped to the Output White value. If clipping is off, the resulting pixel values can be less than
the Output Black value or greater than the Output White value and are affected by the Gamma value.
Levels (Individual Controls) effect
The Levels (Individual Controls) effect functions like the Levels effect but allows you to adjust the individual color
values for each channel. As a result, you can add expressions to individual properties or animate one property
independently of the others. To see each control individually, click the arrow next to the channel color to expand it.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.