I am working with the "real.dat" data found on the following site:


However, the data is missing the central column of gray values where Chroma equals zero. Does anyone know where I can find those values?


1 Answer 1


These are attempts to calculate the equivalents of Munsell color book samples seen in a certain standard light.

Link http://www.rit-mcsl.org/MunsellRenotation/real_CIELAB.xls has CIELAB equivalents of 1943 incarnation.

My best effort to complete the set with greys would be to take the CIELab numbers of Munsell colors with Chroma=2, keep L and set a and b to zero. As an evidence I have this screenshot from Wikipedia's explanations about CIELab:

enter image description here

The asterisks in L*, a* and b* are for making difference between CIELab and another color system which also has L, a and b.

CIE XYZ and xyY numbers can be calculated from Lab numbers, if they are needed.I have never done it.

If I was forced to say something about CIExyY - how to interpolate the greys there, I would say "Keep Y, set x=y=0,33" Unfortunately I cannot prove nor verify it because the formulas of X, Y, Z and the derived xyY are out of my zone of competence.

  • I used ColorMine to convert from CIELAB to CIExyY and got x = 0.3127, y = 0.3290. These values stay the same for every value of Y. This is good enough for me, thanks!
    – posfan12
    Aug 23, 2018 at 22:38

This site is temporarily in read-only mode and not accepting new answers.

Not the answer you're looking for? Browse other questions tagged .