Adobe After Effects CS4 - Manual (Page 539)

533 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Original (left), and with effect applied (right)
Amount Of Noise The amount of noise to add.
Noise Type Use Color Noise adds random values to the red, green, and blue channels individually. Otherwise, the
same random value is added to all channels for each pixel.
Clipping Clips color channel values. Deselecting this option causes more apparent noise. This control does not work
in a 32-bpc project.
Noise Alpha effect
The Noise Alpha effect adds noise to the alpha channel.
This effect works with 8-bpc color.
Noise The type of noise. Unique Random creates equal amounts of black and white noise. Squared Random creates
high-contrast noise. Uniform Animation creates animated noise, and Squared Animation creates animated high-
contrast noise.
Amount The magnitude of the noise.
Original Alpha How to apply the noise to the alpha channel:
• Add Produces equal amounts of noise in the transparent and opaque areas of the clip.
• Clamp Produces noise in the opaque areas only.
• Scale Increases the amount of noise proportionate to the level of opacity and produces no noise in 100%
transparent areas.
• Edges Produces noise only in partially transparent areas, such as the edge of the alpha channel.
Overflow How the effect remaps values that fall outside the grayscale range of 0-255:
• Clip Values above 255 are mapped to 255. Values below 0 are mapped to 0.
• Wrap Back Values above 255 or below 0 are reflected back into the 0-255 range. For example, a value of 258 (255+3)
is reflected to 252 (255-3), and a value of -3 is reflected to 3.
• Wrap Values above 255 and below 0 are wrapped back around into the 0-255 range. For example, a value of 258
wraps around to 2, a value of 256 wraps around to 0, and a value of -3 wraps around to 253.
Random Seed An input value to the random number generator for the noise. This control is active only if you choose
Uniform Random or Squared Random.
To produce flashing noise, animate the Random Seed control. To create smoothly animated noise, animate the Noise
Phase value.
Noise Phase Specifies the placement of noise. This control is active only if you choose Uniform Animation or Squared
Animation.
Noise Options (Animation) How noise is animated.
• Cycle Noise Produces a cycle of noise that plays through once in the specified amount of time.