数字图像多水印算法中的随机共振检测器研究

Study of stochastic resonance detector in a digital image multiple watermarking algorithm

主要研究了一种基于随机共振检测器的数字图像多水印算法。首先将多水印信息调制为不同码率的二进制脉冲幅值调制信号,然后选取图像DCT域中不同段中频系数进行置乱,依据加性数字多水印的嵌入算法,对于数字水印信息的加密过程进行了改进。这种多水印信息的特点使得双稳态非线性系统成为一种比较合适的检测器。这种非线性检测器具有较好的鲁棒性,可以检测出不同码率的数字多水印。实验表明,这种加密和检测方法对于噪声污染、JPEG压缩和剪切等多种攻击具有较好的效能。

This paper presents a digital image multiple watermarking algorithm based on stochastic resonance. First, we map the multi-watermark messages into binary pulse amplitude modulated signals with different code rates, and then add the multi-watermark massages to different DCT coefficients of an image in medium frequency domain. The selected DCT coefficients are disarranged by Arnold transform. According to the characteristic of multi-watermark, we employ a non-linear bistable detector to detect the multi-watermark massages. This kind of non-linear detector will not only detect watermarks with different code rates, but also be more robustness than a linear detector. Finally, the experimental results show that this algorithm can resist against several attacks, such as JPEG compression, cut attack, adding Gauss noise and so on.