Patch codes with improved robustness

摘要

A method for encoding information on a printed page includes generating a set of color patches, each having a unique color. The set of color patches is printed. The printed color patches are scanned to identify color values for each patch in the set of patches. For each patch, the identified color values are associated with a datum value in a data structure. A page which includes a patch code is printed. The patch code includes selected ones of the set of color patches for conveying information about the printed page. The printed page is scanned to identify the color values for the color patches in the patch code. The data structure is accessed to identify the data values for the identified color values of the patches in the patch code. Information about the printed page is determined from the identified data values.