Efficient reversible data hiding based on the histogram modification of differences of pixel differences

Histogram modification is one of the most successful reversible data hiding methods. Among many histogram-modification techniques, difference-histogram-based methods perform well, but the efficiency of difference-histogram-based methods is still unsatisfactory. In this paper, we propose a novel reversible data hiding method based on the differences of pixel differences (DPD). Our method consists of two parts. In the first part, the DPD of cover image is computed to generate the DPD histogram. DPDs that are greater than the position of the peak point of DPD histogram are shifted to the right. Then the secret data is embedded into the pixels associated with the peak point. In the second part, we compute the DPD of the pixel sequence generated by the first part to generate a DPD histogram and shift DPDs that are less than the position of the peak point to the left. As the secret data is embedded into the pixels related to the peak point, the higher the peak point is, the more messages can be embedded. Compared with difference histogram, DPD histogram has a higher peak point, so the embedding capacity is increased. What’s more, we extend the proposed method to a high-embedding-capacity method. Experimental results demonstrate the superior performance of our method and the extended form.