User guide

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Chapter 6, Setting Up Realtime Effects with Adobe Premiere
Overview of the luma key effect
You can use the Matrox realtime plug-in to apply a luma key to make certain
areas of a foreground video clip transparent based on the luminance in that
image, so that an underlying video clip can show through.
In the following example of a luma key effect, two video clips are combined to
produce the effect of two cowboys riding through fire. Our foreground image is a
video clip of a ring of fire against a black background, and our underlying image
is a video clip of two men riding horses:
By luma keying on the particular luminance (brightness) of the black areas in the
foreground clip, these areas become transparent and the corresponding areas of
the underlying image show through in the composite image as follows:
¡ImportantYou must apply the Matrox luma key effect to the clip that contains
the luminance on which you want to key (that is, your foreground image on a
superimpose track). To create a realtime luma key effect, both the foreground and
underlying images must be video clips. If you want to use a graphics clip, you
can export that clip from the Timeline to a single-frame .avi file, then replace the
graphics clip on the Timeline with your exported file.
Foreground image
Underlying image
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Result of luma key
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