An image processing apparatus includes a job execution unit configured to execute at least one of an input job accompanied by inputting of image data and an output job unaccompanied by inputting of image data, an image data storage unit configured to store image data in a predetermined memory, a reference information storage unit configured to store reference information to the image data stored in the memory in the same memory, and a control unit configured to control the image data storage unit to newly store image data in the memory when the job executed by the job execution unit is an input job, and the reference information storage unit to store the reference information to the image data stored in the memory without newly storing image data in the memory when the job executed by the job execution unit is an output job.