一种基于NSST域LU分解的新型零水印算法

A New Zero Watermarking Algorithm in NSST Domain Based on LU Decomposition

文章在数字图像版权保护方面提出了一种基于LU分解和非下采样剪切波变换(NSST)的新型零水印算法.算法首先将载体图像进行NSST变换,并将该子块图像由Logistic混沌系统从低频近似图像中提取.然后将子块图像分解为互不重叠的大小子块.其次将每一个子块图像进行LU分解,并通过判别子块U矩阵首行元素之和与所有子块首行元素之和平均值的数值大小产生零水印.实验结果表明,该算法在加性噪声、滤波、JEPG压缩等方面表现出较强的鲁棒性,而且在一定程度上能抵抗剪切和几何攻击.

A novel zero-watermark algorithm is proposed based on LU decompositionAndNon-Subsampled Shearlet Transform（NSST） in the copyright protection of digital images. In this method, firstly the host image is performed with NSST, and a sub-image is extracted from the low-frequency approximation image by Logistic chaotic system, then the sub-image is divided into non-overlapping sub-blocks. Next, each sub-block is performed with LU decomposition, the zero-watermark is derived by judging the numerical relationship between the sumfrom the first row elements of each sub-block＇s U matrix and the mean of the sums from the first row elements of all sub-block＇s U matrix. Experimental results show that the method is robust to adding noise, filtering and JPEG compression, and can resist the Cropping and RST attack to some ex- tent.