User guide

KeylightThe Foundry
ADVANCED KEYING
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Screen Matte
You may also see dark red pixels which indicate areas where an outside
matte has been used to reduce the transparency of the image.
Screen Matte
The Screen Matte (Figure 38) is the result of pulling the blue or the green
from the image (Figure 36) and making those regions transparent.
Once you have done this you will want to firm up the foreground (make it
more white) and clean up the background (make it more black). This can be
done by processing the Screen Matte using the Clip Min and Max
parameters on the main Keylight PPG or the more extensive parameters on
the Processing PGG.
Pre Blur This blurs the source image before pulling the key. It does not blur the
screen matte that is created after the key is pulled. This process can
improve the key from very grainy blue or green screens.
Figure 36. Green screen.
Figure 37.
Figure 38. Screen Matte.