可抵抗JPEG压缩的鲁棒可逆水印

提出一种可用于半脆弱认证的鲁棒可逆水印算法。该算法利用了鲁棒的统计量-图像均值，通过计算相邻两个图像子块均值的差分，根据差分的范围，将差分进行不同程度地平移来嵌入水印；再根据差分的平移量分别调整两个子块的各个像素，以保证算法的可逆性。同时该算法利用分块直方图调整来避免像素的溢出。对常见图像和三类医学图像（CT、超声波、X光图像）进行仿真实验，发现该可逆水印算法对JPEG压缩具有良好的鲁棒性。与Ni的算法相比，该算法具有更好的图像质量。

Robust Reversible Watermarking Scheme against JPEG Compression

A novel reversible watermarking scheme is proposed,which is robust against high-quality JPEG compression.By computing the difference between the means of two adjacent image blocks,employing it to embed the watermark,and using block histogram shifting to avoid overflow/underflow,this technique receives both losslessness and robustness.If the watermarked image does not change at all,the watermark can be extracted out correctly and the original image can be recovered losslessly.If the watermarked image is compressed to some extent,the watermark can still be correctly extracted for semi-fragile authentication.The scheme is successfully applied to three kinds of medical images and commonly used images.Experimental results show that the high visual quality of images,the pure payload,and the robustness of the proposed scheme against compression are acceptable for many applications,including semi-fragile image authentication.