Patent ID: 7271923

Claim:
An image processing apparatus for input print data of page description language comprising: coded representation generation means for analyzing the print data of page description language and generating band coded representations in a unit of band having a predetermined height; rendering means for rendering bitmap data in a unit of band based on the band coded representations; memory means for storing the bitmap data for one band rendered by said rendering means; coding means for selecting a coding method from plural coding methods and encoding the bitmap data stored in said memory means by the selected coding method; and decoding means for selecting and performing a first decoding method of decoding the bitmap data coded by said coding means and transferring the decoded bitmap data decoded by the decoding means to a printer engine in realtime, or selecting and performing a second decoding method which needs to render the decoded bitmap data decoded by the decoding means into a work memory before transferring the decoded bitmap data decoded by the decoding means to the printer engine, in accordance with the coding method selected by said coding means, wherein a decoding method performed by said decoding means is predicted on the basis of the analysis result by said coded representation generation means, and if the predicted decoding method is the second decoding method, the band height is reduced to half of the band height of the first decoding method.