基于混沌加密和零树编码的彩色图像水印算法

为了保证水印嵌入具有速度快、易实现的优点,并且提高其安全性和鲁棒性,文中利用混沌系统的优良特性,首先对一个有意义二值图像进行快速混沌加密,然后依据零数编码思想对小波系数按重要性排序,选取最重要的L个系数作为水印的嵌入点,即对人类视觉最重要的部分,在其位平面内嵌入加密过的水印,最后反变换得到嵌入水印后的载体图像。试验证明,该算法具有效率高、抗压缩能力强、较好的鲁棒性等优点。

A Color Image Watermarking Algorithm Based on Chaotic Encryption and Zerotrees Coding Idea

In order to insure the watermarking embedding merits,such as high speed,easy realization,etc.and improve its safeness and robustness,a meaning binary image is encrypted quickly based on chaos theory because of chaos system merits.Then the wavelet coefficients are arrayed by their importance and the most important number L coefficients,the part which is most important to the human vision,is selected as the spot which should be embedded by watermarking.At last the watermarking is embedded in the coefficient bit plane and the carrier image containing the watermarking is acquired by the retransform.The experimental result proves that this algorithm has merits such as high efficiency,strong ability to resist compression,better robustness,etc.