Patent ID: 8203748

Claim:
An image processing apparatus comprising: storage means for storing a plurality of electronic data as target comparison images; input means for inputting a whole image of one printed sheet as one reference comparison image by electrically reading a whole image of the one printed sheet to produce a scanned image of an already-printed sheet, wherein a plurality of page images are laid out on the one reference comparison image; page number setting means for determining the number of page images laid out on the scanned image of the already-printed sheet as the one reference comparison image inputted by said input means; segmenting means for segmenting the whole image of the scanned image of the already-printed sheet, inputted as the one reference comparison image, into a plurality of regions corresponding to the page images laid out on the one reference comparison image, based on both of the number of page images determined by said page number setting means to be laid out on the scanned image of the already-printed sheet and an orientation of the whole image of the scanned image of the already-printed sheet inputted as the one reference comparison image, and for further segmenting each of the plurality of regions corresponding to the page images into blocks having different attributes, wherein said segmenting means comprises means for performing two different segmenting operations based on different parameters, the first segmenting operation comprising a page-number-and-image-orientation-based page segmentation for segmenting the whole image of the scanned image of the already-printed sheet into regions each having a different page therein based on both the number of page images determined by the page number setting means to be laid out on the scanned image of the already-printed sheet and the orientation of the whole image of the scanned image of the already-printed sheet inputted as the one reference comparison image, and the second segmentation operation comprising a pixel-based segmentation operation for segmenting each page-image region containing one page into blocks having different attributes; extraction means for extracting each feature amount corresponding to each of the page images by extracting a feature amount from each of the blocks; and retrieval means for retrieving, from said storage means, a plurality of target comparison images corresponding to the page images laid out on the one reference comparison image by using each feature amount corresponding to each of the page images extracted by said extraction means.