Image error concealment and quality access control based on data hiding and cryptography

This paper proposes a data hiding scheme that integrates the dual purpose of error concealment and quality access control of digital image(s) in a single platform. The objective is achieved through the extraction of some important information from the original image itself followed by embedding the same in the host data as watermark which in turn increases sufficient redundancy in the transmitted image. The data embedding is done by modulating integer wavelet coefficients using quantization index modulation (QIM). The watermarked integer wavelet coefficients are then encoded using convolution coding at high code rate. Before data embedding, the important information (watermark) is also encoded with convolution coding and is encrypted using chaotic logistic mapping. The necessary information in the form of the secret key (K) is further encrypted using a public key (P) cryptology for its secret transmission to the receiver. The user who has the knowledge of the secret key (K) can decrypt the hidden information for the concealment purpose, while the users having different partial knowledge of the key (K) enjoy relative qualities of the images by partial recovery of the damaged regions. The simulation results have shown the validity of the claim. The performance of the proposed scheme is also tested in Rayleigh-fading wireless channel and compared with the few other methods.