In the case in which an image processing mode is a high-speed copy mode in which follow-up control is possible, setting is made to perform "follow-up control" for setting a mode for not compressing an image or a fixed length compression mode for an image read by a scanner, storing an inputted image in a memory in accordance with the setting, and outputting the image stored in the memory to a printer during scanning. Consequently, image input/output processing from input and storage of an image in the memory until output of the stored image can be performed at high speed.