I want to design a program that can help me assess between 5 pre-defined colors which one is more similar to a variable color, and with what percentage. The thing is that I don't know how to do that manually step by step. So it is even more difficult to think of a program.
More details: The colors are from photographs of tubes with gel that as different colors. I have 5 tubes with different colors were each is representative of 1 of 5 levels. I want to take photographs of other samples and on the computer assess to which level that sample belongs by comparing colors, and I want to know that with a percentage of approximation too. I would like a program that does something like this: http://www.colortools.net/color_matcher.html
If you can tell me what steps to take, even if they are things for me to think and do manually. It would be very helpful.
One of the best methods to compare two colors by human perception is CIE76. The difference is called Delta-E. When it is less than 1, the human eye can not recognize the difference.
There is wonderful color utilities class ColorUtils (code below), which includes CIE76 comparison methods. It is written by Daniel Strebel,University of Zurich.
From ColorUtils.class I use the method:
r1,g1,b1 - RGB values of the first color
r2,g2,b2 - RGB values ot the second color that you would like to compare
If you work with Android, you can get these values like this:
r1 = Color.red(pixel);
g1 = Color.green(pixel);
b1 = Color.blue(pixel);
ColorUtils.class by Daniel Strebel,University of Zurich: