Section 13.2 Matte - NewTek tricaster advanced edition User Manual

Of course, if you choose poor settings, foreground areas may inadvertently be cut away as well. Good keying
often requires judicious balance between 'too much' and 'too little'. Let's consider the tools TriCaster
provides to help you achieve a great result.
The term Matte refers to a black and white representation
defining the transparent
(foreground) parts of an image during compositing.
Portions of the matte that are grey are treated as semi-
transparent, which is very useful in progressively smoothing
edges between foreground source material and inserted
background imagery.
FIGURE 13-3
Initially, LiveMatte removes a specific color from the foreground image. This color is chosen using the Color
button. To choose this key color, click on the Color sample box and keep the mouse button depressed. Drag
the eyedropper tool over one of the video monitors to choose the color you wish to remove and then release
it. The neighboring 'color well' is updated to show the color selected.
Hint: Enable the Lumakey switch to disregard hue, and base the effect solely on luminance.
No physical greenscreen is perfectly comprised of one color. Wrinkles, folds and shadows along with the
seemingly inevitable uneven lighting result in difference. For this reason, TriCaster provides a numeric slider
labeled Tolerance just beneath the Color picker.
The Tolerance setting allows you to broaden the range considered as the key color, including more 'near-
neighbor' colors to be included in the matte. A low tolerance removes only color values close to the primary
or key color. As you raise the tolerance, you extend the range of values on either side of the primary color
that will be treated as transparent. This allows you to deal with those imperfections we mentioned.
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SECTION 13.2
(background) and
COLOR
13.2.1
TOLERANCE
13.2.2
MATTE
opaque
TriCaster's supplies a digital version of this
traditional tool. The controls under the
Matte label, as you would expect, allow you
to define and adjust the matte for the
corresponding video input.
FIGURE 13-4