Grass Valley Karrera Video Production Center v.4.0 - Manual (Page 53)

KARRERA — User Manual 53
Section
3
Video Mix/Effects
Introduction
This section provides information about switcher features and function-
ality that directly affect video content (images), for example: modifying,
processing, routing, and manipulating images in space.
MEs and Keyers
An ME is a subsystem of a video production switcher that can create a com-
posite of two or more pictures. An ME includes multiple source selection
buses and provides transition (mix and wipe) and keying capabilities on
the selected signals.
Keyers are used to insert part of one picture into another to create a com-
posite picture. Keying involves three signals:
• background,
• key cut, used to specify where to cut a hole in the background, and
• key fill, used to fill the hole in the background. The fill can be an
incoming video signal or it can be an internally generated matte.
A separate key cut input signal is not necessarily required for keying. For
example, a self key (also called a video key) uses the same input signal for
both key cut and key fill.
The Karrera system supports the following types of keys:
• Linear Key (fixed and adjustable)
• Luminance Key
• Preset Pattern
• Chroma Key (option)
The Karrera system also supports self keys and split keys.