摘要
提出了一种基于混沌动力系统同步原理的非对称数字水印构造方法。将二值水印图像转化为二进制数字信号,控制混沌驱动系统两路交替输出信号,形成载有水印信息的混沌信号,并将其作为水印信号嵌入载体图像。水印提取过程中将提取出的水印信号送入混沌响应子系统,根据响应子系统的输出信号与水印信号的相关性来恢复水印图像。在水印嵌入及提取过程中使用不同的混沌系统模型、参数及状态变量初值,实现了非对称数字水印系统的构造。
A method of making an asymmetric digital watermarking based on chaotic synchronization theory is proposed in this paper. Firstly, we transform the double value watermark image into binary digital signals that control the alternative output of two-way chaos signals in chaotic driving system. Secondly, we embed the final chaotic signals which are loaded with watermark information into the carrier image. During the watermark extraction process, we input the watermark signals extracted from the carrier image with watermark information into the chaotic response system, and revert the watermark signals to the watermark image according to the relativity between the outputting signals of chaotic response system and the watermark signals. Different chaotic models, parameters and initial values of variable in watermark embedding process and extraction process are applied; therefore, the digital watermarking on the theory of chaotic synchronization is an asymmetric digital watermarking.
关键词
混沌同步
非对称数字水印
混沌键控
小波变换
chaotic synchronization
asymmetric digital watermarking
chaotic shift keying
wavelet transform