Method of encoding digital information

摘要: This invention provides self-clocking glyph shape codes for encoding digital data (35) in the shapes of glyphs (36) that are suitable printing on hardcopy recording media. Advantageously, selected so they tend not to degrade into each other when degraded and/or distorted as a result, example, being photocopied, transmitted via facsimile, scanned-in an electronic document processing system. Moreover, at least some applications, desirably composed printed pixel patterns containing nearly same number ON pixels and OFF pixels, such code is rendered by substantially uniformly spaced centers appears have generally uniform texture. In case higher spatial densities, this texture likely be perceived gray tone. Binary image convolution filtering techniques decoding also disclosed, but application focuses codes.