基于小波系数能量差值的音频“零数字”水印算法

提出了一种基于小波系数能量差值的音频“零数字”水印算法。对原始音频信号进行小波分解，通过选取适当的阈值，根据逼近系数分量和细节系数分量的能量差值与阈值的大小关系，实现对水印信息的“嵌入”和提取；在提取过程中结合线性伸缩恢复来消除时间轴上线性伸缩带来的影响。实验结果表明，该算法对多种音频文件的操作和攻击，如低通滤波、重采样、重量化、回声干扰、MPEG编码等均具有良好的鲁棒性。

Audio zero-digital watermarking algorithm based on energy difference of wavelet coefficients

An audio zero-digital watermarking algorithm based on energy difference of wavelet coefficients was proposed. Original audio signal was decomposed by wavelet transform. And the energy differences of the approximation coefficients and detail coefficients were collected and classified into two classes according to the relationship between the energy differences and the thresholds. In this way, the watermarks were embedded and extracted. The restoration of the linear scaling was used to resist the influence of the linear scaling on time axis. The experimental results show that this algorithm is robust to many operations and attacks on digital audio signal, such as low-pass filtering, re-sampling, re-quantifying, echo jamming and MPEG encoding.