Improved Reversible Data Hiding Based on Residue Histogram Shifting

This paper proposes an improved reversible data hiding method for grayscale images. Specifically, this method integrates the superiority of two existing schemes to improve secret data capacity. The main idea of this method is to classify image blocks into smooth or complex ones and then to implement disparate reversible data hiding schemes on them. In data embedding process, our hybrid method uses difference expansion transform and residue histogram shifting to carry secret data adaptively without any distortions. Experimental results show that the proposed method improves the problem of low capacity for complex image from 0.02 to 0.39 bpp. At the same time, it indeed provides a good image quality of PSNR in comparisons with previous methods.