Special Issue Article
Modified Difference-Histogram based Reversible Data Hiding Scheme
A Reversible Data Hiding (RDH) is a technique which can retrieve both the cover image and hidden data without any distortion from the watermarked image. In this paper, a new reversible data hiding scheme is proposed based on two-dimensional difference histogram modification by using difference-pair-mapping (DPM). DPM is a new technique and it is an injective mapping defined on difference-pairs. This technique is a natural extension of expansion embedding and shifting techniques. By using this technique, the image redundancy can be better exploited by DPM and an improved embedding performance is achieved. In addition with DPM, a pixel-pair-selection strategy is also adopted to priorly used pixel-pairs located in smooth image regions to embed data. This leads to further enhancement in the embedding performance.