Included are: a platen on which documents to be read are placed; an image input unit configured to read in one or a plurality of documents placed on the platen at one time; a storage unit configured to store entire image data including individual images of the documents read in at one time; an outer frame region removing unit configured to remove, from the entire image data, image data of an outer frame region at a perimeter edge portion of the platen, having a predetermined width; and an individual image cropping unit configured to crop individual images of one or a plurality of documents, from the entire image data after the image data of the outer frame region has been removed.