Way beyond my paygrade, but this 'Shop tut seems to address the issue, maybe, kinda sorta

http://www.dgrin.com/showthread.php?t=21648

& for rocket science

http://vision.ai.uiuc.edu/~qyang6/publications/eccv-10-qingxiong-yang.pdf 

"Our method is based on a key observation - the maximum fraction of the diffuse color component (so called maximum diffuse chromaticity in the literature) in local patches in color images changes smoothly. Using this property, we can estimate the maximum diffuse chromaticity values of the specular pixels by directly applying low-pass filter to the maximum fraction of the color components of the original image, such that the maximum diffuse chromaticity values can be propagated from the diffuse pixels to the specular pixels. The diffuse color at each pixel can then be computed as a nonlinear function of the estimated maximum diffuse chromaticity." 

Or they may be talking about calculating the tea output of China for all I know. 

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken