A specific bit pattern (or set of bit patterns) that have particular frequency and length requirements is used to remove low-frequency, visually observable structure from rendered embedded digital data. In use, the pattern is replicated enough times to be able to XOR with the data before rendering as glyphs, or the like. On decoding (reading), the read data is XOR'd again to recover the original data.
Unique patterns of glyphs are represented within blocks. Each pattern identifies a unique position on a unit of print media. Moreover, a desired current position for any given glyph or subset of glyphs can be derived from captured portions of different ones of the unique patterns. The unique patterns are outputted for subsequent delivery to instances of the unit of print media.
A record and related method is provided for storing encoded information comprising a storage media, first marks on the storage media having a covert code characteristic, with the first marks conveying a covertly marked code and second marks preferably having an overt code characteristic which convey a second overtly marked code useful in decoding the covertly marked code.
