关键词: 无损数据隐藏, 层次结构, 差值直方图, 直方图平移

Abstract: In order to solve the shortage of employing hierarchical relationships of original images in reversible data hiding based on difference histogram shifting, this paper develops a novel reversible data hiding algorithm based on hierarchical structure and difference histogram shifting RDH-HSDHS. Firstly RDH-HSDHS uses the pixel differences of original image’s blocks to form difference histogram, and then utilizes the high correlations between neighbor pixels to embed data. In order to employ the reference pixels in blocks further, RDH-HSDHS rearranges these reference pixels to form the next embedding layer. This multiple-layer embedding procedure will be stopped until the current layer’s embedding capacity is less than the side information for decoding or the output image’s quality is lower than a given threshold value. Experimental simulation results demonstrate that the proposed algorithm makes use of the overall and local characteristic of original image for obtaining the larger number of secret bits for embedding, with good quality of the output images. When the marked image’s quality is larger than 30 dB, the embedding capacity can reach more than 0.75 bit/pixel. In addition, the proposed algorithm outperforms conventional methods based on difference histogram shifting. The presented algorithm is compatible to carry out secret information hiding in digital image with high quality requirement.

Key words: reversible data hiding, hierarchical structure, difference histogram, histogram shifting