Measuring Instruments

Giving Shape to Ideas

Precise Color Communication

The CIE 1976 UCS Diagram was defined by the CIE in 1976. It is intended to provide a perceptually more uniform color spacing for colors at approximately the same luminance. The values of u' and v' can be calculated from the tristimulus values XYZ (or ) or from the chromaticity coordinates xy according to the following formulas:
X, Y, Z:
Tristimulus values (If tristimulus values are used, the results will be u'10 and v'10.)
x, y:
Chromaticity coordinates (If chromaticity coordinates x10 y10 are used, the results will be u'10 and v'10.)

This color difference formula modifies the lightness, saturation, and hue (L*C*h) of the L*a*b* color space by incorporating factors that correct for variation in perceived color difference magnitude in different areas of the CIE 1976 L*a*b* color space. This was proposed in 1994 by the technical committee of CIE.

Back to top