Matte Filters Available in Final Cut Pro
There are three matte filters used most often in conjunction with the Chroma Keyer:
 Eight-Point Garbage Matte: Use this filter to create an eight-point polygonal matte.
This is useful for cropping out unwanted elements surrounding a foreground
element with a complex shape.
 Four-Point Garbage Matte: Use this filter to create a simple four-point polygonal
matte. This simplifies the process when the shape you want to remove can be
encompassed in four points.
 Matte Choker: Use this filter to eliminate any faintly remaining blue or green fringing
or pixels surrounding the edge of your foreground subject. Instead of simply
shrinking the size of the blue-screen clip’s alpha channel, however, which might
result in the accidental elimination of part of your foreground subject, the Matte
Choker selectively shrinks only those parts of the layer’s alpha channel that have a
marginal degree of transparency, such as barely keyed-out blue or green fringing.
Note: Instead of relying solely on the feathering and edge thinning controls of the
Chroma Keyer filter, you should allow some fringing when you adjust the Chroma Keyer’s
settings, so that you can more precisely eliminate fringing with the Matte Choker.