CIE 1964 uniform colour space
3-dimensional, approximately uniform colour space produced by plotting in rectangular coordinates U*, V*, W* quantities defined by the equations:
W* = 25 Y1/3 - 17
U* = 13 W* (u - un)
V* = 13 W* (v - vn)
NOTE 1 Y, u, v describe the colour stimulus considered, and un, vn describe a specified white achromatic stimulus, where .
See also "CIE 1976 uniform chromaticity scale diagram"
NOTE 2 The difference between 2 stimuli, ∆E*, is defined as the Euclidean distance between the points representing them in U*V*W* space and calculated as:
∆E* = [(∆U*)2 + (∆V*)2 + (∆W*)2]1/2.
NOTE 3 This colour space is obsolete (except that it is still used in the calculation of colour rendering index). The currently recommended object colour spaces are CIELAB and CIELUV.