Detecting blank compressed bitmaps in an image output process

摘要

In an image formation apparatus, a compressor image compresses bitmap data obtained by bitmapping image data to be output to generate compressed data. A white plane deciding section compares a size of the compressed data generated by the compressor with a size of compressed data of image data in a blank state, and decides that an output of the image data is in the blank state when both sizes coincide with each other. A task scheduler changes the priority order of tasks based on a result of the decision.