A New SMVQ-Based Reversible Data Hiding Scheme Using State-Codebook Sorting

A reversible data hiding scheme makes it possible to extract secret data and recover the cover image without any distortion. This paper presents a novel reversible data hiding scheme based on side-match vector quantization (SMVQ). If the original SMVQ index value of an image block is larger than a threshold, a technique called state-codebook sorting (SCS) is used to create two state-codebooks to re-encode the block with a smaller index. In this way, more indices are distributed around zero, so the embedding scheme only needs a few bits to encode the indices, which produces more extra space for hiding secret data. The experimental results indicate that the proposed scheme is superior to some previous schemes in embedding performance while maintaining the same visual quality as that of VQ compression.