【摘要】 设计了一个基于离散混沌动力系统和小波分解的数字图像水印算法。在水印图像预处理阶段,利用Logistic映射生成的混沌序列对水印图像进行扩展置乱,再利用Logistic映射生成密钥来对水印信息进行加密,从而保证了水印信息的安全性。在水印图像嵌入阶段,对宿主图像进行三层小波分解,利用小波系数大小关系将水印嵌入到水平方向的高频系数中。分析和实验结果表明,该算法具有良好的鲁棒性,水印的安全性和不可见性明显优于常见算法。更多还原

【Abstract】 This paper designed a digital image watermarking algorithm based on a dispersed chaotic mapping system and wavelet transform.In the process of preprocessing watermark,the Logistic mapping produces key to encrypt the grey value in the pixel to insure the security of watermark.In the process of embedding watermark,three-level wavelet decomposition on image is conducted and watermark is embedded in the high frequency wavelet coefficients according to the size of wavelet coefficients.Analysis and experiment results show that the algorithm possesses relatively strong robustness,and better security and transparency than ordinary algorithms.更多还原