Patent ID: 7859704

Claim:
An image forming apparatus, comprising: an image scanning unit configured to scan an original and obtain image data of the original; an image data size measuring unit configured to measure a data size of the image data corresponding to one page of the original scanned by the image scanning unit; an image data storing unit configured to store in a memory the image data obtained by the image scanning unit; a storable page number calculating unit configured to calculate a storable number of pages of the original that can be stored in the memory based on the data size measured by the image data size measuring unit and available space in the memory; an automatic document feeder; and an operations panel, wherein in response to the storable number of pages calculated by the storable page number calculating unit being less than a total number of pages of the original, the image data of the original is successively stored in and deleted from the memory; and in response to the automatic document feeder detecting that the original is placed therein, the operations panel displays the storable number of pages calculated by the storable page number calculating unit before sort printing is executed.