I have a comprehensive implementation, in Mathematica, of a whole set of color image encoding and decoding processes. My code includes 3x3 matrix transforms, OETF/OECF and EOTF/EOCF mappings, code for chroma subsampling, and code for plotting. I have code to convert among many color systems. Much of the code on the net has been developed to enable checking-off items in feature lists, but has been ported without great care and without much testing or verification. I have gone back to the original sources, and I have done a great deal of testing to ensure that my numbers can be trusted. I used this code to produce the matrices and other numerical data, and graphs and illustrations, in my book. I have ported some of this code to C, to enable rapid simulation and validation of image coding systems.
If you are implementing hardware, firmware, or software to do color image encoding, decoding, or processing, my code would help you generate optimized processing elements. The implementations are my own; the intellectual property is unencumbered.
Call me if you're interested in gaining access to this code.