Reversible image hiding scheme using predictive coding and histogram shifting

In this paper, a reversible image hiding scheme based on histogram shifting for medical images is proposed. As we know, the histogram-based reversible data hiding is limited by the hiding capacity, which is influenced by the overhead of position information that has to be embedded in the host image. To solve this problem, the similarity of neighboring pixels in the images was explored by using the prediction technique and the residual histogram of the predicted errors of the host image was used to hide the secret data in the proposed scheme. In addition, the overlapping between peak and zero pairs was used to further increase the hiding capacity.According to the experimental results, a higher hiding capacity was obtained and a good quality stego-image was preserved in the proposed scheme. The hiding capacity provided by the proposed scheme was approximately three times that of the original histogram-based method. Compared to the histogram-based method, the quality of the stego-image improved about 1.5 dB when the same amounts of secret data were embedded.