结合混沌与提升小波的多功能图像水印系统

基于混沌系统和提升小波变换提出了一种新的图像多功能数字水印系统。首先，对图像整体进行3级提升小波变换，将实现版权保护功能的不可见水印经广义Arnold映射置乱后嵌入图像小波低频系数，嵌入算法采用一种新的双参数量化算法，并能进行盲提取。然后，在图像空域嵌入实现版权通知功能的可见水印，嵌入算法采用加权融合方式，嵌入权重系数由三维混沌系统序列确定。实验结果表明，可见水印能被合法者完全消除，但很难被非法者消除；不可见水印对图像的质量影响很小，并对常规图像处理操作具有良好的鲁棒性。

Multipurpose image watermarking system based on chaos and lifting wavelet

A multipurpose image watermarking system based on chaotic systems and lifting wavelet is proposed.Firstly,the host image is performed 3-level Lifting Wavelet Transformation（LWT）.Based on a novel dual parameters quantization technique,the invisible watermark for copyright protection is embedded in the low frequence coefficients of LWT domain after being permutted by general Arnold map.Secondly,by using the chaotic sequences,visible watermark for copyright notification is embedded in the image spatial domain.Simulation results show that the visible watermark can be removed entirely by le-gal users and can hardly be removed by illegal users,the impact of the invisible watermark on the image quality is slight,and the invisible watermark is robust to common image processing operations.