How to compute Correlation of red- and green-channel pixel values of skin lesion area

I need to compute six correlation coefficients (red-green, green-blue, blue-red, red-grey, green-grey, and blue-grey) for both the whole sub-image and the lesion area respectively,one example shall do it for the 6 as of the same logic shall be applied,as well as calculating the Energy based on color extraction not texture or regionprops one(R,G,B,Gray) but one color space example shall do.. thanks

Answer 1

[Image Analyst]

Did you try corr()?

coeff = corr(redChannel(:), greenChannel(:));

[Elias Unk]

I just tried "corr2" after i got an error on "corr" and worked.. thanks, got an idea about the Energy cz i'm finding different formulas for example Energy = sum (Prob.*Prob) where the author claimed this value is a mean-square of probabilistic function where, where Prob density value in each corresponding pixel intensity is multiplied together and summed out to be the energy of region of interest, and somewhere else it was energy = sum(abs(details(:)).^2);

[Image Analyst]

For normal optical or radiometric images, the gray level already has units of energy. If you don't know why, or don't believe me, just work out the units from first principles using illuminance, exposure time, and size of a pixel.

[Elias Unk]

i do know they exist was just wondering if you have the formula cause i found 2 different ones to compute it and i mentioned them in my comment above.

[Image Analyst]

Use histogram() or histcounts() to get "Prob" in the first formula.

For the second formula, I have no idea whatsoever what "details" is.