1. An apparatus for collecting histogram data for an output image to be presented on a display device, comprising: an input image, the input image containing N bits per image pixel, a mapper, the mapper converting the input image into the output image, the output image having n bits per pixel, where N>n, a histogram collector, the histogram collector forming a histogram of the output image by storing a pixel intensity distribution of the output image; and a histogram equalization function adjustment subroutine, the function adjustment subroutine redefining boundaries of output image pixel intensity distribution present in the histogram such that existing output image pixel intensities are substantially evenly distributed across a range of intensities available to the display device.