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.