How to Choose Colours Procedurally

Re:How to Choose Colours Procedurally by jacobolus on Sunday September 01, 2013 @11:09PM (#6313278)

UPLab is not a “slight tweak” of CIELAB. It’s a lookup table for going back and forth between CIELAB and a slightly rotated version of Munsell space, https://en.wikipedia.org/wiki/Munsell_color_system

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Re:How to Choose Colours Procedurally by taliesinb on Monday September 02, 2013 @08:32AM (#6314838)

You can look at it that way. You can also see it as a modification of cylindrical LAB.

Explain your "slightly rotated" comment?

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Re:How to Choose Colours Procedurally by jacobolus on Monday September 02, 2013 @11:58PM (#6318782)

From Lindbloom’s site: “The mapping was done such that Munsell hue 2.5RP has a UP Lab hue angle of zero degrees. This particular rotation was chosen to allow greater chroma encoding of blue colors in the lower right quadrant of the a/b plane.”

Also, to be completely precise, it should be noted that the lightness dimension of UPLab was left the same as CIELAB’s lightness, rather than using Munsell value. Only a and b were adjusted to reflect Munsell hue/chroma.

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