Tektronix 2200 Manual Do Utilizador

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3-11
Keys
Linear Key
linear key is similar to a luminance key except that the gain of 
the key is set to a value of one (also called “unity”) so that the 
edges of anti-aliased key sources are faithfully reproduced. Anti-
aliased sources, such as the output of a character generator or 
graphics system, have soft edges that produce a mix between the 
fill and the background at the key edge. A linear key preserves 
this edge, as well as DPM soft edges, drop shadows, etc. 
Preset Pattern Key
preset pattern key or preset wipe is a key in which the shape of a 
wipe pattern cuts the hole in the background video. The fill video 
is selected on the Key bus, and the Wipe pattern controls and 
menus are used to select and adjust the key source pattern.