How do I find the absolute color of someone's eyes in a photograph?

Question

The color of my eyes is between green and blue. I've always been curious if it's more blue or more green. People's opinions are of course different, so I would like to find it out scientifically.

How can I analyze colors in picture with computer software and get statistics of colors in it? I would like to know how much blue it is and how much green it is.

And, I am not only interested in finding that about my eyes: I would like to know how to find the color of anybody's eyes. For example, how much brown it is. I don't think this is possible with an RGB scale. I think statistical output with all or defined colors and their percentages would be neat. Is there a way, or do I really need to rely solely on peoples opinion?

This is my left eye and this is my right eye.

Answer 1

First, you have to calibrate the colors in the picture. You'll need a calibrated target such as http://www.bhphotovideo.com/c/product/651253-REG/X_Rite_MSCCPP_ColorChecker_Passport.html

Then you can adjust the colors in the photo to match the target's calibration.

Of course, the definition of color varies, and you get different values if you are using different color spaces. But this will get you started.

I have no idea how you handle that different people see the same color differently. Perhaps that is more in the area of psychology.

Answer 2

I don't think you're going to be successful using photographs. You'll have too many variables. The light temperature, intensity, and overall quality will affect how the iris appears. The camera sensor will be another one. Even under the same lighting conditions, different sensors may record different renditions. Next, the RAW processor (or automatic JPEG conversion) will also influence hue.

I think a non-photographic solution will be your best bet for repeatable and accurate eye color assessment.