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colorimetric purity


where Ld and Ln are the respective luminances of the monochromatic stimulus and of the specified achromatic stimulus that match the colour stimulus considered in an additive mixture

Note 1 to entry: In the case of purple stimuli, the monochromatic stimulus is replaced by a stimulus whose chromaticity is represented by a point on the purple boundary.

Note 2 to entry: In the CIE 1931 standard colorimetric system, colorimetric purity, pc, is related to excitation purity, pe, by the equation pc = pe yd / y where yd and y are the y chromaticity coordinates respectively, of the monochromatic stimulus and the colour stimulus considered.

Note 3 to entry: In the CIE 1964 standard colorimetric system, a measure, pc,10, is defined by the relation given in Note 2 to entry, but using pe,10, yd,10 and y10 instead of pe, yd, and y respectively.

Note 4 to entry: This entry was numbered 845-03-47 in IEC 60050-845:1987.

Note 5 to entry: This entry was numbered 17-195 in CIE S 017:2011.

Publication date: 2020-12
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