inconspicuous_male

inconspicuous_male t1_iyk6mbm wrote

Reply to Is there a consistent and objective way to assess the color of an object? A transform function from spectrum to RGB, maybe? by DJTilapia

I don't have the time right now to type out a detailed answer, which sucks because I have a color science degree... I'll give you a quick rundown though.

When you have a spectral measurement, you multiply the spectrum received by the eye to color matching functions. You can find these online. They're based on the spectral sensitivity of the human eye, but there's some neuroscience that goes into transforming from cone sensitivity to color matching. The three dimensions are called CIE XYZ. CIE is a French organization that srandarduzes color measurment. Y is significant because it contains all of the information about sharpness and perception of brightness, but the X Y Z responses (which we can call chromaticity) are device invariant, so the transform from XYZ to RGB can be determined for any given monitor if you have spectral information about the RGB of the monitor (or if you assume the monitor is close to display standard).

L*a*b* is the color space typically used for matching reflective matetials. Lightness and a/b are three parameters that make up color when combined with a spectrum of an illuminant.

I suggest the Wikipedia article on Color Science, because it's a huge topic that can't be explained well without visual aids and graphs. But google CIE XYZ, Lab color space, chromaticity coordinates

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