Matrox Electronic Systems Matrox RT.X2 - Manual (Page 99)

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Overview of the chroma key effects
Overview of the chroma key effects
You can use the Matrox realtime plug-in to apply a chroma key or chroma key
shadow effect to make certain areas of a foreground image transparent based on a
color in that image, so that an underlying image can show through.
In the following example of a chroma key effect, our foreground image is a video
clip of a woman sitting in front of a green backdrop, and our underlying image is
a video clip of a sand dune:
By chroma keying on the particular shade of green in the backdrop of the
foreground image, the backdrop area becomes transparent and the corresponding
area of the underlying image shows through in the composite image as follows:
¡ Important The chroma key shadow effect includes controls for fine-tuning
shadows in your effect. It is best to use the chroma key shadow effect when you
are performing a chroma key without any additional effects. If you want to apply
additional effects to your chroma key, you will get more desirable results by
using the chroma key effect without shadow controls. For example, if you want to
apply a DVE to your chroma key, you should use the chroma key effect and not
the chroma key shadow effect.
Foreground image Underlying image
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Result of chroma key
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