复合NSCT分解DCT变换和SVD分解的多重变换水印

Multiple transform domain watermarking algorithm based on NSCT decomposition DCT transform and SVD decomposition

为了提高水印的抗旋转攻击鲁棒性,加大水印的嵌入量,提出了一种基于非采样Contourlet变换(NSCT)和离散余弦变换(DCT)结合的双重变换域水印算法。对图像进行NSCT变换,将低频系数进行DCT变换,对DCT域低频系数进行奇异值分解(SVD)。经仿真实验表明,该算法对常规滤波、旋转有很好的鲁棒性,特别面对旋转攻击时,算法仍能很好地提取出水印信息。

This paper proposes a new algorithm based on Nonsampling Contourlet Transform （NSCT） and Discrete Cosine Transformation （DCT） to improve the watermarking＇ s anti-rotation attack robustness and the embedding quantity. It transforms the image with NSCT, then does the low-frequency coefficients with DCT, decomposes the low-frequency coefficients of DCT domain with Singular Value Decomposition（SVD）. Experimental results show that the algorithm has a good robustness in filter and rotation, and extracts the watermarking very well in rotation attack especially.