基于差值域直方图平移的密文可逆水印算法

Reversible watermarking algorithm for encrypted image based on histogram difference shifting

为了满足密文域水印可逆嵌入的需要,利用一种直方图平移与同态加密相结合的技术,提出了一种新颖的差值域直方图平移密文图像可逆水印算法。该算法可以在没有原始图像信息的情况下直接对密文域图像嵌入水印,即实现原始图像—加密—水印嵌入的过程,从而简化了传统算法中原始图像—加密—解密—水印嵌入—加密的冗余过程。仿真实验表明,该算法可以在图像失真度很低的情况下,有效提高嵌入容量,而且水印完全提取,图像无失真恢复。实验效果明显好于其他算法。

To meet the watermarking requirement in encrypted domain,this paper proposed a novel reversible watermarking algorithm in histogram difference domain for encrypted image by utilizing a combination of histogram shifting and homomorphic encryption. It could embeded a watermark into the encrypted image directly to realize the process of plain image-encrypted image-watermark embedding,which simplified the traditional redundant process of plain image-encrypted image-decryption-watermark embedding-encryption again. Simulation experimental results demonstrate that the proposed algorithm can provide greater payload capacity and higher image fidelity. After it extracts the watermark completely,it can recover the original image reversibly. It outperforms other related algorithms.