Grass Valley Indigo AV Mixer v.1.2.2 - Manual (Page 53)

INDIGO AV Mixer User Manual 53
Video Processing
Chroma Key
A chroma key is a key that detects color (rather than luminance) in a video
image and replaces it with a new background. For example, a reporter may
be in a studio sitting in front of a backdrop with a blue or green backing
color, and the new background can be a mountain scene. The completed
chroma key consists the mountain scene replacing the backing color, cre-
ating the illusion that the reporter is sitting in front of the mountain.
Figure 31. Chroma Key
X
X
+
Suppression
Background Video Key Hole Background
Chroma Key
Chroma Key Source
Completed
Invert
Chroma Key
(video only)
Primary
Gain
Clip
Invert
Suppression
Chroma Key
Secondary
Key Control Backing Colors Selected
Chroma Key Fill
Backing Color Suppressed
Chroma Key Fill
Backing Color Removed