Legibility of text in an image of a page is determined by comparing a measure of the text in the page image with a measure of the page image itself. In one aspect, a measure of the text in the page image may be the height of a line of text, while the measure derived from the page image may be the height...http://www.google.de/patents/US7466875?utm_source=gb-gplus-sharePatent US7466875 - Method and system for determining the legibility of text in an image
