1. A page segmentor comprising: dividing means for dividing a page into a plurality of areas, multiplying means for multiplying an image of one of the plurality of areas into a plurality of identical, smaller images, said multiplying means including a single convex lens having a relatively large aperture size, the image of the area being located at a focal point of said single convex lens, and a plurality of convex lenses each having a relatively small aperture size, said plurality of convex lenses being aligned on a side of said single convex lens opposite the image of the area in a direction perpendicular to an optical axis of said single convex lens in an optical path of light passing from the image of the area through said single convex lens, feature extracting means for simultaneously extracting features of the area by optically detecting the presence or absence of a correlation between each of pairs of the plurality of smaller images and a plurality of different masks, said plurality of masks including at least one mask for detecting a laterally written document having character strings written horizontally across the page, and at least one other mask for detecting a vertically written document having character strings written up or down the page, and merging means for merging two or more of the areas which have identical single features, wherein the page is further divided by the dividing means into progressively smaller areas until each of the areas has a single feature.