Box blur effect, Channel blur effect, Compound blur effect – Adobe After Effects CS4 User Manual
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USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
When Colorize is selected, the Bilateral Blur effect operates on each color channel individually. The result is a color
image.
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Box Blur effect
Box Blur is similar to Fast Blur and Gaussian Blur, but Box Blur has the added advantage of an Iterations property,
which allows you to control the quality of the blur.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
Iterations
How many times the blur is sequentially applied to the image. A value around 3 gives a blur similar in
quality to Fast Blur. A higher number of iterations creates smoother transitions between colors and increases the blur,
but it also increases the render time. The default value creates boxy results.
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Channel Blur effect
The Channel Blur effect individually blurs the red, green, blue, or alpha channels of a layer.
Note: If you have noise or artifacts primarily in one color channel—such as MPEG compression artifacts in the blue
channel of DV footage—use Channel Blur to clean up the noise in that channel, leaving the other channels sharp.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
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Compound Blur effect
The Compound Blur effect blurs pixels in the effect layer based on the luminance values of a control layer, also known
as a blur layer or blurring map. By default, bright values in the blur layer correspond to more blurring of the effect layer,
while dark values correspond to less blurring; select Invert Blur for light values to correspond to less blurring.
This effect is useful for simulating smudges and fingerprints, or changes in visibility caused by atmospheric conditions
such as smoke or heat, especially with animated blur layers such as those generated with the Turbulent Noise effect.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.