I have absorbance values for blood plasma. Absorbance was measured in range of 380 – 600 nm every 5 nm ending up with absorbance values for 45 wave lengths. I was browsing through literature, and I came across chromacity coordinates (XYZ) and this seems to be a very convenient way of summarizing data about color in just two data points. I have been reading some literature about different colorimetric systems, but since my background is in genetics, it didn’t make much sense for me. Therefore, I would like to ask you if it is possible to calculate these chromacity coordinates using my absorbance values and if so does anyone now some kind of software for this or exact formulas on how to do it?


why not?

First, you'll need measurements in the range 380 - 780 nm (400 - 700 would be fine too) then, you'll simply apply the color matching functions to it : http://www.cvrl.org/cmfs.htm

I suggest these : Stiles & Burch (1955) 2-deg, RGB CMFs, or these : 2-deg XYZ CMFs transformed from the CIE (2006) 2-deg LMS cone fundamentals

You'll have to transform them into transmittance values first, of course.

I think you can find the protocol here : http://en.wikipedia.org/wiki/CIE_1931_color_space

You will have to choose a standard illuminant, I suggest D65, you'll find excel tables under wikipedia "D65 illuminant"

Tell me if it works


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