A system encodes a separate assist channel that carries only a small amount of additional information in a hardcopy document to compensate for failure of an OCR system to accurately reconstruct a scanned electronic version of the hardcopy document. After the OCR system produces an interpretation of the...http://www.google.co.uk/patents/US7110621?utm_source=gb-gplus-sharePatent US7110621 - Assist channel coding using a rewrite model
