An Efficient Reversible Data Hiding Scheme Based on Reference Pixel and Block Selection

In this paper, we propose an efficient data hiding scheme based on reference pixel and block selection to further improve the embedding performance of histogram shifting. Specifically, we first divide the original image into non-overlapping blocks of an adjustable size. Then for each block, we assign the median of pixels as the reference pixel and the number of pixels equal to the reference value as the smooth level. In this way, difference histograms for each smooth level can be constructed. We embed the secret data using histogram shifting from the highest level histogram to lower level ones instead of sequential embedding. By this means, our proposed reversible data hiding scheme can adaptively embed data in the smooth blocks and thus improve the marked image quality with a comparable embedding capacity. The experimental results also demonstrate its superiority over some state-of-the-art reversible data hiding works.