Apple Final Cut Pro 5 - Manual (Page 996)

Chapter 11 Video Filters 209
II
Difference Matte Compares two clips and keys out areas that are similar. A View pop-
up menu allows you to look at the source of the clip (with no key
applied), the matte created by the filter, the final matted image, or
a special composite of the source, matte, and final image for
reference. The Difference Layer clip control allows you to specify
another clip to compare the current image to for keying. Threshold
and Tolerance sliders let you adjust the key to try to isolate the
parts of your image that you want to keep.
Luma Key Similar to a chroma (color) key, except that a luma key creates a
matte based on the brightest or darkest areas of an image. Keying
out a luminance value works best when your clip has a large
discrepancy in exposure between the bright or dark areas in the
frame that you want to key out, and the foreground images you
want to preserve.
A View pop-up menu allows you to look at the source of the clip
(with no key applied), the matte created by the filter, the final
matted image, or a special composite of the source, matte, and
final image for reference. A Key Mode pop-up menu allows you to
specify whether this filter keys out brighter, darker, similar, or
dissimilar areas of the image. A Matte pop-up menu lets you create
either alpha channel information for that clip, or a high-contrast
matte image applied to the color channels of your clip, based on
the matte created by this filter.
Spill Suppressor - Blue When you use the blue and green screen key to key out the blue in a
clip, sometimes there is residual blue fringing, referred to as spill,
around the edge of the foreground image. This filter removes this
blue fringing by desaturating the edges where the fringing appears.
This filter should always appear after a color key in the filter list
shown in the Filter tab of the Viewer. It may have a slight effect on
the color balance of your image.
Spill Suppressor - Green Works the same as the Spill Suppressor - Blue, on green fringing.
1 Works in 32-bit floating point if your sequence is set for high precision in the Video Processing tab of the Sequence
Settings window.
Filter Result