Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 389

Which values to use as input; the first several items in the menu are actually multichannel combinations of
From
input and output options, so they don't require you to set a To value.
• Saturation Multiplied uses the saturation value multiplied by the lightness value, where lightness is the minimum
distance to black or white. For example, a dark or light blue pixel has a lower value than a bright or pure blue pixel.
This option represents the most common view of a pixel's saturation value.
• Min RGB uses the lowest value among the red, green, and blue channel values.
• Max RGB uses the highest value among the red, green, and blue channel values.
The channels to which to apply the values. Choose Red Only, Green Only, and Blue Only to apply the value to
To
one channel only and set the other color channels to zero. Choose Alpha Only to apply the value to the alpha channel
and set the color channels to 1.0. When you select Hue Only, the applied hue value is combined with 50% lightness
and 100% saturation. When you select Lightness Only, the applied lightness value is combined with 0% saturation,
which then gives the hue no influence. When you select Saturation Only, the applied saturation values are combined
with 0% hue and 50% lightness.
Inverts (subtracts from 1.0) the output channel values.
Invert
Makes the alpha channel value 1.0 (complete opacity) throughout the layer.
Solid Alpha
Compound Arithmetic effect
The Compound Arithmetic effect mathematically combines the layer to which it is applied with a control layer. The
Compound Arithmetic effect is intended only to provide compatibility with projects created in earlier versions of
After Effects that use the Compound Arithmetic effect. Using blending modes is usually more effective than using
the Compound Arithmetic effect.
This effect works with 8-bpc color.
The layer to use with the current layer in the given operation.
Second Source Layer
The operation to perform between the two layers.
Operator
The channels to which the effect is applied.
Operate On Channels
How the effect remaps values that fall outside the grayscale range of 0-255.
Overflow Behavior
• Values above 255 are mapped to 255. Values below 0 are mapped to 0.
Clip
• Values above 255 and below 0 are wrapped back around into the 0-255 range. For example, a value of 258
Wrap
wraps around to 2, a value of 256 wraps around to 0, and a value of -3 wraps around to 253.
• The maximum and minimum values are remapped to 255 and 0, and intermediate values are stretched or
Scale
compressed to fit within this range.
Stretch Second Source To Fit
option is deselected, the second layer is placed at its source's current size, aligned with the upper left corner of the
source layer.
The effect's transparency. The result of the effect is blended with the original image, with the
Blend With Original
effect result composited on top. The higher you set this value, the less the effect affects the layer. For example, if you
set this value to 100%, the effect has no visible result on the layer; if you set this value to 0%, the original image doesn't
show through.
Invert effect
The Invert effect inverts the color information of an image.
Scales the second layer to match the size (width and height) of the current layer. If this
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