1. An image processing apparatus comprising: an image data obtaining unit that obtains image data of an original document including a plurality of pages; a feature amount obtaining unit that obtains a predetermined feature amount for each of the pages based on the obtained image data; a detection unit that compares a feature amount of one page on which identification information for dividing the plurality of pages in units of pages is formed with a feature amount of the other pages and detects the identification information on a page having a feature amount similar to a feature amount of the one page from among the other pages; and a division unit that divides the plurality of pages in units of pages based on the detected identification information.