METHOD OF EXTRACTING BIT STREAM FROM MACHINE-READABLE CODE IN IMAGE, METHOD OF DETERMINING ORIENTATION OF MACHINE-READABLE CODE IN IMAGE, AND APPARATUS FOR EXTRACTING BIT STREAM FROM MACHINE-READABLE CODE IN IMAGE

摘要

PROBLEM TO BE SOLVED: To provide a method and apparatus for locating and decoding a machine-readable two-dimensional code.;SOLUTION: A method of locating and decoding a two-dimensional machine-readable code in a digital image, where the code has three finder patterns adjacent to respective corners of the symbol, and the method takes into account the possibility of skew/pitch when delineating the code in the digital image to estimate the unknown fourth corner, based on lines passing through known symbol edge points. On the basis of the delineating, a reference grid is mapped to the digital image and a bit stream is extracted based on the mapping.;COPYRIGHT: (C)2008,JPO&INPIT