Document #
17 of 19
Revision Date
82070-248, Revision A
1/19/2009
Glossary
Black Level:
This adjustment allows the display to be set to discriminate between small differences in dark
or near black areas of the image. The adjustment should make a black area of the image (such as a deep
shadow where all detail is lost in the image) appear black. The black level is decreased (less black) until a
change toward light or grey is perceived in this area, then the adjustment should be increased slightly to
restore the dark area to black. It is important to perform this adjustment on a truly black area in the image to
avoid making dark areas appear lighter than they actually are.
Brightness:
The intensity of light emitted from the LCD Display. This control is similar to the effect of
changing the light behind a stained glass window. As the illumination is increased the overall light output of
the image is increased. The proper adjustment takes into consideration the ambient light in the room. For a
brightly lit room, the brightness of the display may be increased to improve the visibility of the image. In a
dimly lit room, the brightness may be decreased to reduce the impact on the eye.
Clock:
This adjustment is seldom necessary, but if there is a problem with the frequency of the monitor
pixel clock that it cannot exactly match the clock signal from the camera, an adjustment may be required.
The symptom of a clock adjustment problem is the appearance of vertical bands in the image. Adjustment
of the clock will help eliminate these artifacts.
Contrast:
Contrast is the differentiation between variations of similar colors. Typically contrast is set by
adjusting for best color differentiation between light yellow and white.
Hue:
Hue refers to the “shade” of the colors. Adjustment of this feature is applicable primarily to analog
signal sources. S-Video, RGBHV and VGA are analog signals. Adjustment of hue will help to correct
abnormalities in the signal. The adjustment can help in restoring the “natural” look of the colors.
Phase:
This adjustment is seldom necessary, but if there is a problem with the monitor pixel clock phase or
position in relation to the pixel clock generated by the camera, a phase adjustment may be required. The
symptom of phase problems is the appearance of horizontal lines flickering through the image.
Red, Green, Blue Color Adjustment:
Increasing the bias of a color increases the proportion of that color in
the image. The level of the selected color is varied equally for all proportions. For example:
Color Number 1 Proportions
Bias Increase New Color Proportions
Red = 20%
5%
Red = 20% + 5% = 25%
Green = 70%
0%
Green = 70%
Blue = 40%
0%
Blue = 40%
Color Number 2 Proportions
Bias Increase New Color Proportions
Red = 60%
5%
Red = 60% + 5% = 65%
Green = 40%
0%
Green = 40%
Blue = 30%
0%
Blue = 30%
Note that Red has been increased by 5% regardless of its original proportion.
Since increasing the bias will add additional proportions of the color, care must be taken to assure that
variations for very weak and very intense sections of the image do not lose their “Contrast” (ability to detect
subtle variations between colors).
Saturation:
Saturation refers to the purity of any particular color component (Red, Green or Blue). For
example, 100% Red saturation is 100% Red, 0% Green and 0% Blue. No saturation means all the color
percentages are equal. Changes in saturation will change the emphasis of the selected color component.
