抗JPEG压缩和几何攻击的鲁棒零水印算法

针对数字图像传输时经常面临JPEG压缩和几何攻击,提出一种抗JPEG压缩和几何攻击的鲁棒零水印算法.将原始图像分割成互不重叠的子块,对每个子块进行奇异值分解,对奇异值矩阵进行harr小波变换,通过比较相邻两个子块奇异值矩阵小波低频逼近子带对角线元素的均值大小关系产生零水印序列.数学理论分析表明:通过比较相邻两个子块奇异值矩阵所有奇异值的均值大小关系产生零水印序列,算法实质上没有对原始图像做任何改动,具有非常好的不可见性.实验结果表明,该算法在抵抗JPEG压缩和旋转、尺寸缩放、随机删除行列、偏移行列、打印-扫描几种几何攻击表现出比较强的鲁棒性.

A Robust Zero-watermarking Algorithm Resisting JPEG Compression and Geometric Attacks

A robust zero-watermarking algorithm resisting JPEG compression and geometric attacks is proposed, since digital images always face with JPEG compression and geometric attacks through transmission. An original image is split into non-overlapping blocks, and each block is conducted with singular value decomposition.Then, each block's singular value matrix is transformed with Harr wavelet transformation. The zero-watermark sequence is produced by judging the numerical relation between the mean of diagonal elements of singular value matrix's low frequency band from two adjacent blocks. The mathematical theoretical analysis shows that the zero-watermark sequence is essentially produced by judging the numerical relation between the mean of singular value matrix's singular values from two adjacent blocks. The proposed algorithm has perfect visibility due to no alteration made to the original image. The experimental results show that the proposed algorithm has strong robustness to resist JPEG compression and several geometric attacks such as rotation, scaling, random row & column removal, row & column shifting, print-and-scan.