I did the same thing for browning of french fries. It turned out that RGB was too highly correlated to be efficient so I mapped into an "application specific" c

I did the same thing for browning of french fries. It turned out that RGB was too highly correlated to be efficient so I mapped into an "application specific" color space where the rate was pretty much along a straight line. Kind of like HSV but more specific to the actual cucumber shape of the RGB distribution. https://www.google.com/patents/US5818953 https://www.google.com/patents/US5818953