THOMSON GRASS VALLEY KayakDD-1, User Manual

Page: 40 / 448

KayakDD - Digital Production Switcher
2.10.9 Linear Key
A linear key typically uses separate key cut and key fill input signals that are intended
to be used for linear keying. The key cut and key fill are usually anti-aliased (soft
edged) shaped signals created by a character generator or graphics system. There
may also be translucent areas intended to allow some background to show through the
key (watermarks). The level of the key cut signal determines where and how deeply
the hole will be cut into the background. The intended soft edge and translucency of
the key can then be faithfully reproduced.
Figure 13 Linear Keying
NOTE!
The soft edges in the illustrations in this part of the manual are simulated. The key
edges are actually gradients, which allows these edges to blend smoothly with the
background. In the KayakDD System the Linear Key is just a special parameter setup
of the Luminance Key
40 User Manual