Quality enhancement of printed-and-scanned images using distributed coding

In this paper we address visual communications via print-and-scan channels from an information-theoretic point of view as communications with side information that targets quality enhancement of visual data at the output of this type of channels. The solution to this problem addresses important aspects of multimedia data processing and management. A practical approach to side information communications for printed documents based on Wyner–Ziv and Gray setups is analyzed in the paper that assumes two separated communications channels where an appropriate distributed coding should be elaborated. The printing channel is considered to be a direct visual channel for images (“analog” channel with degradations). The “digital channel” is considered to be an appropriate auxiliary channel exploited to communicate the information exploited for quality enhancement of printed-and-scanned image. We demonstrate both theoretically and practically how one can benefit from this sort of “distributed paper communications”.