Table of Contents
Advertisement
Keys
This section describes the settings for keying operations (excluding chroma
keying) which you can make on the M/E banks or PGM/PST bank.
For details of chroma key operations and settings, see Chapter 5.
Overview
A key is a video effect in which a hole is cut in the background video, and
filled with a different video image, or simply a matte if the shape of the hole
corresponds to titling for example. The video signal which cuts the hole,
determining its shape, is termed the key source signal, and the video used to
fill the hole is termed the key fill signal. A component of the system which
carries out keying is called a keyer.
The DVS-7250 system includes two keyers (KEY1 and KEY2) for each M/E
bank and two downstream keyers (DSK1 and DSK2) for the PGM/PST bank.
Key types
The key type determines the technique used to cut the hole in the background
video. The following five key types are provided.
Luminance key
The hole is cut at a certain level of the Y (luminance) signal of the key
source.
• In a D2 system, the key source is passed through a filter, and the resulting Y
• In a D1 system, the key source Y signal is passed through a filter to apply
4-30
Chapter 4 Basic Operations for Image Creation
signal is used to determine the key.
S-curve compensation, and the resulting signal is used to determine the key.
Advertisement
Table of Contents
