Patent ID: 7673218

Claim:
A system for decoding coded data printed in ink on a surface, the coded data including an encoded bit stream and redundancy data associated with the bit stream, the system comprising: a store for storing the coded data; and a decoder for: determining a codeword format for the coded data; reading from the store, using the determined format, coded data, the coded data being read so as to de-interleave the encoded bit stream and the redundancy data into each of a number of codewords, each codeword including a bit stream part and corresponding redundancy data; correcting, using the bit stream part and the corresponding redundancy data, errors in the encoded bit stream; and writing the corrected data to the store, wherein the coded data includes a registration structure, the registration structure including at least two clock tracks indicative of a position of the coded data in the direction perpendicular to an alignment direction and two alignment lines for each clock track, the two alignment lines being indicative of the position of the respective clock track, and wherein the decoder is for: determining, using an alignment phase-locked loop (PLL), a position of the alignment lines for a respective clock track; determining, using the position of the alignment lines, the position of each respective track; and updating the alignment PLL.