Tektronix 2200 Manual Do Utilizador

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Shaping and unshaping are generally involved only in keying and 
compositing situations.

Whenever a key is performed, there are always three signals: the 
key source, the key fill (fill video), and the background video. The 
key signal cuts a hole in the background, into which the fill video 
is inserted. Devices such as character generators often output both 
the key signal and the fill video.

— Fill video that has been “multiplied” by a key 

signal to produce a raster image to be inserted into a key hole cut 
in background video by the same key signal. (An example of 
shaped video is the fill video output of a character generator, 
which consists of characters on a black matte.)

— Previously-shaped fill or composited video 

that has been unshaped by an unshaping processor which 
“divides” the video by the key signal. The Model 2200, 3000, and 
4000 switchers, as well as some Digital Picture Manipulators 
(DPMs), have selectable unshaping circuits on their outputs.

— Any full-raster (full-screen) video that has 

not previously been processed by a key signal. This is also 
sometimes loosely defined as Unshaped Video. Video sources 
from devices such as cameras are usually full-raster video and 
thus are non-shaped. These sources are not usually accompanied 
by key signals.