1. An image processing apparatus, comprising: a storage device configured to store mode specification information associating a job with a mode, wherein the mode specification information indicates which of a page mode and a band mode is to be selected when the job is performed; a data processing device configured to acquire image data and perform a data processing on the image data; an input device configured to detect a first user operation for inputting the job and a second user operation for starting the job; and a main controller configured to (1) specify the mode corresponding to the job designated by the first user operation, and (2) cause the data processing device to acquire the image data upon detection of the second user operation and to perform the data processing according to the specified mode.