Patent ID: 7375855

Claim:
An image processing apparatus that converts image data expressed by tone values of respective pixels constituting an image into dot data representing dot on-off state, said image processing apparatus comprising: a dot data conversion module that joins a preset number of adjacent pixels into a unit and collectively converts the image data of each unit into the dot data; and a dot on-off state storage module that stores dot on-off state determined with regard to at least part of pixels included in a processed unit, which has been subjected to the data conversion, in such a manner that a pixel position in the processed unit is identifiable, wherein said dot data conversion module comprises: a target pixel specification sub-module that successively specifies a target pixel, in which a dot on-off state is to be determined, in each unit; a dot creation status detection sub-module that detects a dot creation status with regard to an object pixel that is located at a specific position relative to the target pixel, among the at least part of the pixels included in the processed unit, for which the dot on-off state is stored; and a dot on-off state determination sub-module that determines the dot on-off state in the target pixel, based on a tone value of the image data at the target pixel and the dot creation status detected with regard to the object pixel at the specific position.