Keys

A key is an effect in which a part of the background image is replaced by an image or superimposed text. The signal determining how the background is cut out is termed “key source,” and the signal that replaces the cut-out part is termed “key fill.” The system component responsible for processing a key is referred to as a keyer.

Each M/E bank and the PGM/PST bank has four keyers, and all of these keyers provide the same functions.

Key Types

The key type indicates the manner in which the key source signal is used to cut out the background. In each bank, you can use the following key types. You can select the key type using the key type selection buttons in the key control block, or by a setting in the Type menu for the keyer. (See “Key Type Setting” (page 379).)

•Luminance key

•Linear key

•Color vector key

•Chroma key

•Wipe pattern key

•Key wipe pattern key

Luminance key

The background is cut out according to the luminance (Y) of the key source signal, and at the same time the key fill signal is cut out and then added to the background signal.

Linear key

This is a type of luminance key, but there is a reduced variability in gain, allowing more precise adjustment.

Color vector key

The key signal is created from a combination of the luminance and chrominance components of the key source signal. When perfect keying is not possible with a luminance key, this allows a key signal to be created even if the luminance level is low, provided that the colors have high saturation.

48 Keys