The CIE L*C*h or CIELCh color scale is an approximately uniform scale with a polar color space. The CIELCh scale values are calculated from the CIELAB scale values. They are described in Section 4.2 of CIE Publication 15.2 (1986). The L*, lightness, value is the same in each scale. The C* value, chroma, and the h value, hue angle, are calculated from the a* and b* of the CIELAB scale. The CIELCh color space is diagrammed below.
The basic delta values for this scale are ∆L*, ∆C*, and ∆H*. They are the differences between the sample and standard in L*, C*, and h*. The total color difference, ∆E* is the same as the ∆E* in the CIELAB scale.
Another total color difference value often used with this color scale is ∆Ecmc. ∆Ecmc and associated values will be discussed in a separate Applications Note. Please refer to it for further information.
Conditions for Measurement
Instrumental: Any HunterLab color measurement instrument
(See attached for the complete article with illustrations and Mathematical Formulas)