Getting non-normalized Histograms

Is there a way of getting the non-normalized histogram? I am trying to extract intensity or the total pixel intensity within an ROI. The total intensity values of all pixels in an ROI does not need to be derived through the histogram if there is another way of extracting this information.

Thank you

Well, given the w/h of the ROI this is known by working the math backwards?

Just multiply each bin by the width/height of the roi which is what the normalized histogram is removing.