| Definition: | three-dimensional, approximately uniform colour space produced by plotting in rectangular coordinates L* a* b* quantities defined by the equations (4) :
X
X, Y, Z describe the colour stimulus considered and Xn, Yn, Zn describe a specified white achromatic stimulus
NOTE – Approximate correlates of lightness, chroma and hue may be calculated as follows :
CIE 1976 lightness
L* = 116 (Y/Yn)1/3 — 16
Y/Yn >0,008 856
CIE 1976 a, b chroma
C*ab = (a*2 + b*2)1/2
CIE 1976 a, b hue-angle
hab = arctan (b */a *)
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