OPTIMIZING THE CONSTANT-CHANNEL CHROMATICITY AND COLOR GAMUT OF CRT COLOR DISPLAYS BY CONTROL OF BRIGHTNESS AND CONTRAST LEVELS

Before a CRT color display is calibrated, the levels of the brightness and contrast controls should be considered. These levels have differe nt effects on the relationship between the chromaticity coordinates of the red-green-blue (RGB) channels and the voltage applied to the gun as well as on the color gamut. Using three different CRT color display s, we measured both these relationships as well as the color gamut for different combinations of brightness and contrast levels. With respec t to the luminance range of the white point provided by each display, the results show that the assumption of constant-channel chromaticity of the RGB channels is more valid at medium- to low-brightness levels in combination with high-contrast levels. In addition, this assumption holds at high contrast and medium- to low-brightness levels, the colo r gamut being optimized at these combinations of levels, with regard t o the size of the triangle of primaries-the maximum luminance of the d isplay white point. (C) 1996 Optical Society of America