Process for independently protecting two dimensional codes from one or more burst errors patterns

Claim 1

In a method for writing and reading a parity protected binary message of predetermined symbol size into and from, respectively, a two dimensional code; the improvement comprising the steps of padding said message with a predetermined set of constant bit values to provide a first array of bits that is symbol aligned for certain scan patterns, where the only variables are message bits; reading out said first array in accordance with a predetermined one of said scan patterns to provide a first set of symbols that are a disjoint cover of said array; computing at least one symbol oriented error correction code on said first array of bits to produce parity symbols for protecting said message against an anticipated burst error pattern; encoding said message and a selected number of said parity symbols in said code; decoding said code for recovering decode values for said message and for said parity symbols; separating the decode values for said message from the decode values for said parity symbols; padding said message with said predetermined set of constant bit values to provide a second symbol aligned array of bits that is identical to said first array, subject only to any decode errors that may have corrupted said message; reading out said second array in accordance with said predetermined one of said scan patterns to provide a second set of symbols that are identical to first set of symbols, subject only to any decode errors that may have corrupted said message; and computing a decode of said error correction code on said second set of symbols and said parity symbols to correct said decode errors if and when possible.