Patent ID: 8724124

Claim:
An image forming apparatus that sets an output unit configured by a plurality of pages of which the order is determined as one copy and outputs a plurality of copies of output units as a JOB, the image forming apparatus comprising: an image forming unit that sequentially forms images corresponding to the plurality of pages on a plurality of sheets; a control unit that performs a calculation process of image eigenvalues that are based on the images for each of the output units; a first storage unit that stores a result of the calculation process performed for a reference copy of the output unit that is a specific one copy out of the plurality of copies of the output units; and a second storage unit that stores a result of the calculation process performed for a copy of output unit other than the reference copy of the output unit out of the plurality of copies of the output units, wherein the control unit determines whether or not images are normally formed on the plurality of sheets for the copy of the output unit other than the reference copy of the output unit based on a result of comparison between the result of the calculation process which is stored in the first storage unit and the result of the calculation process which is stored in the second storage unit and, in the case where a negative determination is made, stores a place determined to be negative, and continues to output the JOB without stop.