Example: Using the Four-Point Garbage Matte Filter
The following example illustrates how to use the Four-Point Garbage Matte filter to
eliminate the outside edges of a clip being keyed.
1
Apply the Four-Point Garbage Matte to the clip being keyed. Open this clip in the
Viewer, then click the Filters tab.
∏
Tip: It may be easier to see what you’re doing if you disable the Chroma Keyer, Matte
Choker, and Spill Suppressor filters first.
2
In the Four-Point Garbage Matte filter, click the Point 1 point control.
Click the Point 1 point
control to start changing
the matte.
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Keying, Mattes, and Masks
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3
Move the pointer to the Canvas (the pointer turns into a crosshair pointer), then click to
change the location of the matte corner defined by Point 1.
4
Repeat steps 2 and 3 for the Point 2, Point 3, and Point 4 point controls, until you’ve
created a box that crops out everything outside the green screen surrounding the actor.
5
To round the four corners of the matte, adjust the Smooth slider, if necessary.
6
If necessary, adjust the Choke and Feather sliders.
Before changing the location
of the first point
After changing the location
of the first point
The matte, with rounded
corners
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Effects
The Choke slider adjusts the overall size of the matte, without changing the shape; the
Feather slider blurs the edges of the matte.
The parameters of the Garbage Matte filters can be keyframed, in the same way as the
parameters of any other filter. This can come in handy if you need to use one of the
Garbage Matte filters to crop out the outside edge of a green screen in a shot where
the camera is panning.