1. A computer implemented method for processing image intensities on a computing device comprising: displaying an image on a display device having a range of intensities; subdividing the range of intensities from the image on the display device into a set of intensity zones; associating each intensity zone with one or more segments of a graphical diagram to be displayed on a computer device; and moving a partition separating the one or more segments of the graphical diagram displayed on the computer device to change the intensity levels of the displayed image.