Algorithm for text page up/down orientation determination

Abstract We present an algorithm that operates on a bit-mapped text pattern array to determine the up/down orientation of the page, that is, whether the page is upright or inverted. The algorithm exploits an up/down asymmetry of passages of text composed of roman letters and arabic numerals. A computer program that implements the algorithm is listed. Experimental results from electronically received facsimile (fax) pages verify the effectiveness of the algorithm.