A method for processing scanned code data, including a plurality of strings, to determine whether the scanned code data is part of a valid code begins by examining a first string of a first scanned code data. A cluster is opened with the first string if the first string contains a start pattern. At least one valid middle portion of the first string is identified and a transition position count associated with the at least one valid middle portion is stored. A second scanned code data is searched for a second string matching at least part of the first string in the cluster. If a match is found, then the second string is added to the end of the cluster. The cluster is closed upon detection of a stop pattern and is then decoded.