Tektronix AVG1, User Manual

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Glossary
Glossary- 2
AVG1 Analog Video Generator User Manual
Hardware Modulation
When signals are hardware modulated, digital data from the C
B
and C
R
channels are quadrature modulated at the subcarrier frequency and added to
the luminance (Y) channel. This method is used for NTSC signals in cases
where the best nonlinearity specifications are required. The hardware
modulator is also used to create YC composite signals (SVHS or Hi-8).
Luminance
The signal which represents brightness, or the amount of light in the picture.
This is the only signal required for black and white pictures, and for color
systems it is obtained as a weighted sum (Y = 0.3R + 0.59G + 0.11B) of the
R, G, and B signals.
Modulated
When referring to television test signals, this term implies that chrominance
information is present. (For example, a modulated ramp has subcarrier on
each step.)
Modulation
A process which allows information to be moved around in the frequency
domain in order to facilitate transmission or frequency-domain multiplexing.
See Hardware and Software modulation for details.
NTSC
National Television System Committee. The organization that developed the
television standard currently in use in the United States, Canada and Japan.
Now generally used to refer to that standard.
PAL
Phase Alternate Line. Refers to one of the television systems used in Europe
and many other parts of the world. The phase of one of the color difference
signals alternates from line to line to help cancel out phase errors.
Quick Draw Mode
Enables an overlay to draw faster while you are changing values. Full
resolution is invoked once values stop changing.
R--Y
One of the color difference signals used in the NTSC and PAL systems,
obtained by subtracting luminance (Y) from the red camera signal (R).