A new model of QIM data hiding for quality access control of digital image

This paper proposes a data-hiding scheme for quality access control of digital images using a new model of quantization index modulation (QIM). An encoded binary watermark is embedded over N-mutually orthogonal signal points using QIM but without complete self-noise suppression. It is well known that due to insertion of external information, there will be degradation in visual quality of the host image (cover) that plays the key role in access control through reversible process. 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. The self-noise is suppressed by authorized user to provide better quality image. The simulation results have shown the validity of those claims.