Superimposing and Compositing > Creating garbage mattes
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Creating garbage mattes
Sometimes the subject of a scene is properly keyed except for undesired objects. Use a garbage matte to mask out those objects. You can then place the keyed subject in another scene for simple effects.
The microphone (left) is masked out by repositioning image handles in the Transparency dialog box (center), creating a garbage matte that is then keyed and superimposed over a background (right).
To create a garbage matte:
1 Select a clip in a superimpose track and choose Clip > Video Options > Transparency. For more details, see Using keys to superimpose and create composites.
2 In the Sample area of the Transparency Settings dialog box, drag the handles of the image to include only the subject you want to preserve.
3 Choose a key to key out the background of your subject. Then click OK.
Superimposing and Compositing > Creating garbage mattes