Apple Final Cut Pro 7 - Manual (Page 1053)

Result Filter
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 luma 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. Luma Key
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 Filters tab of the Viewer. It may have a slight
effect on the color balance of your image. Spill Suppressor - Blue
Works in the same way as the Spill Suppressor - Blue filter, but on
green fringing. Spill Suppressor - Green
1 Works in 32-bit floating point if your sequence is set for high-precision rendering in the Video Processing tab of the
Sequence Settings window.
Matte Filters
Matte filters can be used by themselves to mask out areas of a clip, or to create alpha
channel information for a clip to make a transparent border so that the clip can be
composited against other layers. Matte filters can also be used to make further adjustments
to layers with key filters applied to them. For detailed information, see
“Using Mattes to
Add or Modify Alpha Channels.”
Result Filter
Generates an eight-point polygon you can use to crop out portions
of a clip. Eight-point controls allow you to define the polygonal
matte. The Smooth slider rounds off the corners of the polygon to
create rounder mattes. The Choke slider allows you to expand or
contract the matte, and the Feather slider allows you to blur the
edges of the matte. The Invert checkbox reverses what’s matted
and what’s transparent, and the Hide Labels checkbox hides the
number labels, which indicate which point of the matte corresponds
to which point control of the filter. Eight-Point Garbage Matte
1053 Chapter 65 Video Filters Available in Final Cut Pro