DATA HIDING FOR QUALITY ACCESS CONTROL AND ERROR CONCEALMENT IN DIGITAL IMAGES

This paper proposes a data hiding scheme to serve dual purpose of quality access control and error concealment of digital images. This is accomplished by projecting host image first on N-mutually orthogonal sample sets followed by embedding of an encoded binary watermark (host digest) using quantization index modulation (QIM) but without complete self-noise suppression. It is well known that due to insertion of external information, there would be degradation in visual quality of the host image. This has been used here to play the key role in access control through reversible process and error concealment using the extracted image digest. Decision variable for each bit of watermark decoding is formed from the weighted average of N-decision statistics that increases the correctness of extracted watermark bits. This improved detection enables self-noise suppression by authorized user, error concealment in fading radio mobile channel and thus leads to avail better quality image. Simulation results have shown the validity of our claims along with relative comparative results for other existing works.