Histogram Comparisons In Matlab

I have made some noticeable progress since Monday in that i have devised a system that finds me squares of images depending on a density and window size and for each creates a histogram and compares against a blank one. However i ahve had issues normalising these so that they equal 1. Some issue with the fact matlab doesn't properly bin the data but rather ranges it...explained better by an example image. It is infact the way matlab bins these histograms that ruins my chi squared algorithm.