Knox Video VS-200 - Manual (Page 52)

K NOX V IDEO VS-200 O PERATION M ANUAL
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10 COMMON OPERATIONS
This section provides step by step instructions for some common operations.
10.1 Operation of the Keyer
Some units come equipped with a very powerful Luminance and Chrominance
Keyer. The Keyer can take some time to master and below is a breakdown and
series of simple steps to help you master the Keyer’s operation
When adjusting the values, please bear in the mind the following:
The Y value is the Luminance value, so 0 is black and 255 is very bright (white).
The U value is the B-Y component. This is the difference between the Blue and the
Luminance value. If part of an image is black, grey or white, then its value is 128
(being the mid-point).
The V value is the R-Y component. This is the difference between the Red and the
Luminance value. If part of an image is black, grey or white, then its value is 128
(being the mid-point).
10.1.1 Preparation:
1. Enter the Adjust windows menu.
2. Select the Source (this will be the foreground).
3. Exit the Adjust windows menu.
4. Enter the Adjust keyers menu.
5. Ensure the Keyer is Off.
6. Set all Y, U and V min/max values to [0] [255].
7. Set all Y, U and V softness values to 0.
8. Set all Y, U and V invert values to Off.
9. Turn the Keyer On.
At this point your source image will have disappeared, since all colors have been
keyed out.
10.1.2 Adjustment:
Knowing which color(s) you want to key out from the image, e.g. black to disappear,
perform the following set of steps:
1. Increase the Y Key Min from 0 until just before the required color (Key Color)
appears.
2. Decrease the Y Key Max from 255 until just before the required color (Key Color)
appears.
3. Repeat steps 1 & 2 for the U and V min/max values as well.
Adjust any of the Softness values to improve the key. If your input signal is slightly
noisy or if you want to soften the edges within the image, then this may require you