【摘要】 提出了一种改进的基于PDE的数字水印算法,该算法先利用二维logistic混沌映射对水印图像进行置乱变换,并将置乱后的水印划分成两部分水印。利用偏微分方程分解模型对载体宿主图像进行分解,生成卡通和纹理两个部分。根据卡通和纹理两部分的图像复杂度的不同,分别对其进行DWT和SVD,再将已生成的两部分水印按照加性方式分别嵌入到二级小波变换的低频部分和SVD的对角矩阵中。结果表明,该算法不仅有很好的不可见性,而且对Gaussian噪声、JPEG压缩以及低度旋转等攻击具有很好的鲁棒性。更多还原

【Abstract】 This paper presents an improved digital watermark algorithm based on PDE.In this paper,we firstly took advantage of logistic chaotic mapping to scramble the watermark image and divided the scrambled watermark image into two parts.Then PDE was used to decompose the host image into cartoon and texture components.And then,DWT and SVD were selected to handle cartoon and texture respectively according to the complexity of these two parts.Lastly,the two watermark images were respectively embedded into the low frequencies of DWT and the diagonal matrix of SVD.Experiments show that the scheme proposed not just has good invisibility,but also has excellent robustness for some conventional watermark attacks such as JPEG compression,Gaussian noise and rotation.更多还原