基于纠错编码和扩频技术的同步音频水印算法  

A Synchronous Audio Watermarking Algorithm Based on Error Correction Coding and Spread Spectrum Technology

作　　者：殷雄[1] 张晓明[1] 

机构地区：[1]北京石油化工学院自动化系

出　　处：《北京石油化工学院学报》2007年第4期43-48,共6页Journal of Beijing Institute of Petrochemical Technology

摘　　要：利用混沌动力力学系统中的logistic映射对水印图像进行置乱处理,并且引入扩频技术和纠错编码技术。然后对公开音频信号进行离散小波变换,并将音频的中低频小波系数划分为若干包含相等样点的片段,对于每个片段的前半段和后半段的能量进行统计,根据秘密信息的比特位,采取不改变或缩小音频信号的振幅的方法来进行嵌入秘密信息。算法在隐藏水印信息的同时,嵌入一个同步信号,使水印具有自同步能力。实验结果表明,隐藏有秘密水印信息的载体音频听觉质量没有明显下降,提取的水印信息感知质量较好。此外,该算法在受到基本攻击时几乎都具有很强的鲁棒性。Firstly, the image watermark is encrypted by the logistic-map sequences in chaotic dynamical systems. And error correcting and spread spectrum technology is adopted. Then, the discrete wavelet transform of public audio signal is performed and the middle and low coefficient of audio DWT is divided into several sections including the same samples. The energy of the first half and the second half of each section has been calculated, according to the secret watermark bit and energy processing, the secret watermark has been embedded into the audio signal by adopting the way of not changing or reducing amplitude of the sample point. Fourthly, Synchronization code is embedded into audio signal with the watermark, and the watermark thus generated has the ability of self-synchronization. Experimental results show that the quality degradation of the carrier audio is unperceivable, and the quality of the recovered watermark is satisfying. Besides, the algorithm is robust to attacks of common signal processing manipulations.

关 键 词：音频水印 纠错 扩频 同步 

分 类 号：TN914[电子电信—通信与信息系统]