An image processing apparatus can obtain a copy image having excellent reproducibility with a relatively simple structure of a processing unit that processes image data. The image processing apparatus generates image formation data by processing image data. A gradation processing unit binarizes the image...http://www.google.com/patents/US7633650?utm_source=gb-gplus-sharePatent US7633650 - Apparatus and method for processing binary image produced by error diffusion according to character or line drawing detection
