101: Color Decoder - color and tint

[HD Library]

The color signal that is provided to your display needs to be processed back into RGB drive signals for the display and this is called the color decoder.

Color decoders are set wrong by the manufacturer to attract your attention when deciding which display you like. Many increase the red to offset a blue gray scale which prevents flesh tones from looking dead. Many decrease the green output for the same reason they add blue; you like it and it covers up errors. The main purpose as always is to look different and draw your attention to their product.

There are two settings for the color decoder, phase or tint/hue and amplitude or color level for each primary color. Everybody can adjust the blue signal using the tint and color controls with the appropriate test pattern and a blue filter. If the red and green signals are aligned correctly from the factory then the color decoder will be set correctly when you adjust blue. That is usually not the case though.

If your display provides a means to adjust the red and green signals then you will use red, green and blue filters or better yet the display may provide a means to turn off the other two primary colors while you make the adjustment. Please refer to your calibration disc and owners manual for the instruction set.