基于奇异值变换和多级离散余弦变换的抗旋转攻击盲水印算法

A blind watermarking algorithm against rotation attack based on SVD and multiple-level discrete cosine transform

将contourlet变换和多级离散小波变换的"多级"概念引入离散余弦变换(DCT),对传统的DCT数字水印算法不能有效抵抗几何攻击的缺点进行了定性的分析,提出了一种在离散余弦变换域将奇异值变换(SVD)和多级离散余弦变换(MDCT)相结合的鲁棒性水印算法.该算法首先将宿主图像从笛卡尔坐标系转换到对数极坐标系下,然后对对数极坐标系下的宿主图像进行多级离散余弦变换,再对MDCT后的图像进行奇异值变换,最后将仿射变换后的二值水印图像嵌入到奇异值中.仿真实验表明本文算法对于噪声感染、滤波、JPEG压缩等常规信号处理的鲁棒性优于传统的基于DCT的数字水印算法,同时对于旋转几何变换也具有很好的鲁棒性.

The idea of multiple-level from contourlet transform and discrete wavelet transform is expanded to discrete cosine transform domain,and traditional watermarking methods are analyzed which in DCT domain can＇t resist to geometric attacks.A blind watermarking algorithm against rotation attack based on SVD and multiple-level discrete cosine transform was proposed.Firstly the host image is transformed from Cartesian coordinate to logarithm polar coordinate,then multiple-level discrete cosine transform is applied in LPM.After MDCT,the host image is decomposed with SVD.Finally,the binary watermark image after affine transform is embedded into the singular value of the image.The simulation experiment results demonstrate the proposed method is better than traditional algorithms based on DCT in commonplace signal processing,such as： adding noise,filtering and JPEG compression etc.it is also robust enough for rotation attacks.