为了实现对多媒体数据版权的有效保护,提出了一种基于离散混沌映射和二维离散小波变换的图像水印新算法。该算法利用切延迟椭圆反射腔离散混沌系统(TD—ERCS)产生的混沌序列,将其二值化后加密水印图像,并采用小波变换将加密后的水印图像嵌入到宿主图像的蓝色分量的最深层的四个子带中,嵌入位置则由广义猫映射确定。仿真实验和性能分析表明,该算法具有很好的隐蔽性、鲁棒性和安全性。
To protect copyrights of multi-media data effectively, proposed a novel image watermarking algorithm was based on TD-ERCS map and 2-dimensions discrete wavelet transform. Encrypted the watermark by a chaos sequence, which was generated by TD-ERCS chaotic system, and embeded the encrypted watermark into four sub-bands of the most deep level of blue branch of host image by three-level wavelet transform, and determined the embedded positions by general cat chaotic map. The experiment results show that the algorithm has good invisibility, robustness and security to the watermark.