figure;
        normalized_hist = imhist(uint8(output_image),16)./numel(output_image)
        horz = linspace(0,255,16);
        stem(horz, normalized_hist, 'markersize', 0)
        axis([0 255 0 max(normalized_hist + 0.005)]);
        grid on;

        entropy = 0;

        for i = 1:length(normalized_hist)
            if (normalized_hist(i) > 0)
                entropy = entropy + normalized_hist(i) * log2(normalized_hist(i));
            end
        end
        entropy = -entropy;