Provided is a computer implemented method and interface for mapping image intensities on a computing device. The processing method includes 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.