An image data processing system includes an extracting unit extracting from an image signal corresponding to one image a signal corresponding to a pixel block including plural pixels in the image, a threshold calculating unit calculating a threshold for classifying the plural pixels into plural segments...http://www.google.com.au/patents/US20090080776?utm_source=gb-gplus-sharePatent US20090080776 - IMAGE DATA PROCESSING SYSTEM AND IMAGE DATA PROCESSING METHOD
