Chapter 4 Keys; Overview; Key Types - Sony MVS-8000X User Manual

Keys

Overview

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 the
"key source," and the signal that replaces the cut-out part
is termed the "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 eight keyers,
and all of these keyers provide the same functions.
Notes
• When the signal format is 1080P, four keyers can be
used (keys 1 to 4).
• On the MVS-7000X, the number of available keys
depends on the M/E bank.
For details, see "M/E Configuration Switching (M/E
Split)" (page 207).

Key Types

The key type indicates the manner in which the key source
signal is used to cut out the background.
Type Description
Luminance The background is cut out
key 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.
Type
Color
vector key
Chroma
key
Wipe
pattern key
Key wipe
pattern key
Clean mode
In a luminance key, linear key or color vector key, you can
enable clean mode. When clean mode is enabled, key fill
is added to the background without cutting out with key
source. This improves the keyed image quality, but means
Clean
that the part of the key fill signal which is not to be inserted
mode
must be completely black, or it will color the background.
Supported
You set clean mode in the Type menu for each keyer.
For details, see "Setting the Key Type" (page 98).
In the following situations, clean mode cannot be enabled.
• When the key type is a pattern key
Supported
• When key invert is enabled
• When the key fill is a matte
• When the key edge is an outline
• When the key edge is normal and soft edge is enabled
• When fine key is enabled
• When key positioning is enabled
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Chapter
Description
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.
A key signal based on a particular
color is used to cut out the
background, and the key fill is
then inserted.
This uses the wipe pattern
selected for a transition to cut out
the background, and the key fill is
then inserted.
This uses the wipe pattern
selected for an independent key
transition to cut out the
background, and the key fill is
then inserted.
Clean
mode
Supported
Not
supported
Not
supported
Not
supported