1. An image processing apparatus comprising: an intrablock pixel position judging section for judging pixel position within a block in which pixels constituting image are divided in units of plural pixels; a shifted pixel designating section for designating shifted pixel to be shifted in accordance with the pixel position judged by the intrablock pixel position judging section; a phase calculating section for determining phase quantity of intrablock dot cluster for every block; and a pixel value shift section for carrying out shift from respective pixels within the block to the shifted pixel on the basis of the phase quantity determined by the phase calculating section and, value differences of respective pixels within the block and value of the shifted pixel.