User manual

Front Panel Operations Imagestore HDTV User Manual
Page 62 Miranda Technologies Ltd
Once generated, the Key signal controls the combining of the Background
and Fill video signals. Oxtel series products support both Linear and Full
keying.
Key invert replaces the Key output with 1-Key, thereby inverting the action
of the Key.
Linear keying is used where the Fill signal has been pre-computed to match
the Key signal.
An example of this is where the output of a signal generator requires high
quality keying. If a Full key was used it may cause a darkened border around
characters where the character edge on the Fill signal correlates with the
character edge on the Key signal and the resultant Fill signal after
multiplication would be parabolic.