关键词: 无损信息隐藏, 图像插值, 自适应隐藏, 大容量

Abstract:

Although the hiding capacity of interpolation-based lossless data hiding algorithm is high, image quality of hided image is poor. For this problem, this paper proposes an adaptive high capacity lossless data hiding algorithm based on interpolation technology. Firstly, an improved image interpolation method is proposed, and then the input image is down-sampled, and a new cover image is generated by using the proposed interpolation method on down-sampled image. The cover image is divided into overlapping blocks and the variance of all reference pixels of each block is calculated. According to the variance of all blocks, the sorting operation is processed with ascending and the index of each block is obtained. Secondly, the block is selected by the obtained index and the maximum and minimum of all reference pixels of each block are obtained, and then two differences of each non-reference pixel between the maximum and minimum are calculated, respectively. The final difference of each non-reference pixel is selected adaptably by the magnitude relationship of the absolute value of two differences and the number of bits which can be hidden is computed according to its absolute value of difference. Finally, the adaptive hiding method is used to hide secret data. The proposed algorithm is tested on never-compressed image database (NCID) and USC-SIPI image database. The results show the average data hiding rate of the proposed algorithm is 2.4925 bit/pixel. Compared with similar lossless data hiding algorithms, the results show that not only the hiding capacity of the proposed algorithm is improved by about 90%, but also the image quality of hidden image is also enhanced by about 9% on average.

Key words: lossless data hiding, image interpolation, adaptive hiding, high capacity