A method is provided for encoding two-dimensional frame codes comprising the steps of establishing first and second line bit sequences, determining an exclusive OR (XOR) logic value of the first and second code lines to obtain a two-dimensional matrix of XOR logic values and determining the two-dimensional...http://www.google.es/patents/US6340118?utm_source=gb-gplus-sharePatente US6340118 - Exclusive or cross-coupled framing codes for self-clocking glyphs
Exclusive or cross-coupled framing codes for self-clocking glyphs
