一种非线性数字水印的改进方法

An improved secure algorithm for non—linear digital watermark

主要研究了一种非线性数字水印的改进算法。首先利用差错码控制对数字水印信息进行编码,然后将水印信息调制为二进制脉冲幅值调制信号。依据图像本身视觉和细节特点选取不同段的DCT中频系数进行Arnold置换,并将同一水印分别进行嵌入。采用具有较好鲁棒性的非线性饱和检测系统来提取水印信息。这种改进的水印算法对于噪声,滤波,剪切,压缩等多种攻击具有较好的鲁棒性和抗攻击能力。

This paper studies an improved secure algorithm for the non-linear digital watermark. First, we use error correcting coding to encode the digital watermark information. Then, we modulate the watermark messages into binary pulse amplitude modulated codes, and add the same watermark messages on different sections of DCT coefficients in medium frequency domain, which have been disarranged by Arnold transform according to the features of digital image. We choose a non-linear saturating detector to detect the watermark messages. This kind of non-linear detector possesses better robustness and frequency adaptability. The robustness and the anti-attack capability of the proposed watermarking scheme is shown in various attacks, such as noise, filtering, croping, compression.