Patent ID: 7436547

Claim:
An image processing system for processing images, comprising: an image processing device for implementing a certain image process on image data and an image generating device for outputting images by forming dots based on the results of the image process, the image processing device comprising: pixel group tone value determining unit that determines pixel group tone values representing individual pixel groups, each of pixel groups is composed of a plurality of mutually adjacent pixels; number data producing unit that produces number data for each of pixel groups based on a predetermined correspondence between the pixel group tone value and the number data representing the number of dots formed in the pixel group; error diffusing unit that diffuses a tone error, which occurs between the pixel group tone value and the tone value represented by the number data, among pixel groups for which number data has been not produced yet; and control data output unit that outputs the produced number data as a control data which is used to control the formation of dots by the image generating device which forms images; the image generating device comprising: pixel position determining unit that specifies an order in which dots are formed for each of pixels in the pixel groups, and determines dot position formed in each of the pixel groups based in the specified order and the number data of the pixel groups extracted from the control data that has been provided; and dot forming unit that forms dots based on the determined pixel positions.