PAGE SORTING DEVICE

PURPOSE:To rapidly sort pages for a desired feature by duplicating plural images from one area, extracting the feature of the area by detecting the presence of the optical correlation with relatively different masks, and dividing the area into pieces until each piece of area has only single feature. CONSTITUTION:The titled device is provided with division means 14, 27 to divide the area in a page 11 into plural areas, a duplication means 16 to duplicate plural images 21 from one of the areas, and feature extraction means 22a-22e that extracts the feature of an area by optically checking the presence of a correlation of each pair between the duplicated images 21 and the relatively different masks 23a-23e. And the division of the areas is continued until each area has its own single feature. As a result, plural features can be concurrently extracted, hence a feature corresponding to the shapes of the masks 23a-23e can be extracted at a high speed.