To improve the delay of printing speed which is caused by delay of band compression processing of a subsequent page during extension processing of the image data when compression processing and extension processing cannot be executed simultaneously in an image forming apparatus configured to perform compression extension processing of image data by exclusive hardware.
In the image forming apparatus 1, image data of one page is divided into a plurality of bands, the image data is stored in an HDD 24 after subjected to compression in band units by a compression extension unit 23 of a main controller 2, and when data for one page is stored in the HDD 24, the image data is extended by the extension compression unit 23 and output to paper. An accelerator 3 performs generation of image data and further compresses the image data in band units according to the operation state of the compression extension unit 23 by a compression unit 35, and transfers it to the main controller 2.
Akinaka Takano
Kenichiro Sano
Eiichi Shiragashi