Adobe After Effects CS4 - Manual (Page 461)

455 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Use the Key Out Unsafe and Key Out Safe settings for How To Make Color Safe to determine which portions of the
image the Broadcast Colors effect affects at the current settings.
Note: A more reliable way to keep colors within the broadcast-safe range for your output type is to use color management
features to set the output color profile accordingly, such as to SDTV (Rec. 601 NTSC). This method ensures that color
values in the range 0.0–1.0 in your working color space are converted to broadcast-safe values. (See “
Broadcast-safe
colors ” on page 295.)
This effect works with 8-bpc color.
Broadcast Locale The broadcast standard for your intended output. NTSC (National Television Standards
Committee) is the North American standard and is also used in Japan. PAL (Phase Alternating Line) is used in most
of Western Europe and South America.
How To Make Color Safe How to reduce signal amplitude:
• Reduce Luminance Reduces the brightness of a pixel by moving it toward black. This setting is the default.
• Reduce Saturation Moves the color of a pixel toward a gray of similar brightness, making the pixel less colorful. For
the same IRE level, reducing saturation alters the image more noticeably than does reducing luminance.
Maximum Signal Amplitude (IRE) The maximum amplitude of the signal in IRE units. A pixel with a magnitude above
this value is altered. The default is 110. Lower values affect the image more noticeably; higher values are more risky.
More Help topics
“ Color correction and adjustment ” on page 279
Change Color effect
The Change Color effect adjusts the hue, lightness, and saturation of a range of colors.
This effect works with 8-bpc and 16-bpc color.
View Corrected Layer shows the results of the Change Color effect. Color Correction Mask shows a grayscale matte
that indicates the areas of the layer that will be changed. White areas in the color correction mask are changed the most,
and dark areas are changed the least.
Hue Transform The amount, in degrees, to adjust hue.
Lightness Transform Positive values brighten the matched pixels; negative values darken them.
Saturation Transform Positive values increase saturation of matched pixels (moving toward pure color); negative
values decrease saturation of matched pixels (moving toward gray).
Color To Change The central color in the range to be changed.
Matching Tolerance How much colors can differ from Color To Change and still be matched.
Matching Softness The amount that the effect affects unmatched pixels, in proportion to their similarity to Color To
Change.
Match Colors Determines the color space in which to compare colors to determine similarity. RGB compares colors
in an RGB color space. Hue compares the hues of colors, ignoring saturation and brightness—so bright red and light
pink match, for example. Chroma uses the two chrominance components to determine similarity, ignoring luminance
(lightness).
Invert Color Correction Mask Inverts the mask that determines which colors to affect.