I think the correlation might work for you. For a gray image, you can vectorize them and use xcorr
or corrcoef
functions to get the correlations. For RGB image, if you would like all the details from three channels, you may need to work on the MuPAD Notebook Interface, in which plot::Raster
translates the RGB values into a 2D mesh of rectangles. Then you can implement the correlations.
Another possible quantification of the GNP binding is to apply blood vessel segmentation, and use the result as a mask, then calculate the recall/precision (false positive vs false negative) as a indication of the GNP ability to bind blood vessels.