| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for encoding and decoding a document which contains a machine-readable text overlaid by human-readable content and graphics. <P>SOLUTION: The method includes the step for generating a background image on a substrate. This background image includes coded glyphtone cells, based on grayscale image data values, with each of the halftone cells including one of at least two distinguishable patterns. The method further includes the succeeding step of compounding the background image with a second image, such that the second image is viewed by decoding two or more neighboring visible halftone cells. <P>COPYRIGHT: (C)2004,JPO |
