Method and Apparatus for Encoding and Reading Optical Machine-Readable Data Codes

摘要

A method and apparatus for data encoding and optical recognition of encoded data includes generating symbols that represent data using angles (rather than linear dimensions as used for conventional bar codes). One embodiment uses spirals isocurves. Another uses parabolas isocurves. Methods for visually depicting such symbols, including symbols having gray values are disclosed. Methods for machine-based detection and decoding of such symbols regardless of their orientation relative to the machine is also disclosed.