一种新的扩频音频水印算法  

A New Spread Spectrum Audio Watermarking Arithmetic

作　　者：曹莉[1] 朱晓青[1] 王曦[1] 

机构地区：[1]西安电子科技大学计算机学院,陕西西安710071

出　　处：《微电子学与计算机》2005年第1期81-84,共4页Microelectronics & Computer

摘　　要：音频水印提供了一种数字保密的方法,用来保护作者和版权所有者的权利。在本文中,基于扩频技术提出了一种新的音频水印算法,即应用音频的瞬时平均频率(IMF)来嵌入数字水印,其目标是最大限度的满足水印的不可觉察性和健壮性。本文算法对原始的音频信号进行短时傅立叶变换,从而估计出信号的加权瞬时平均频率(IMF)。基于心理声学模型的掩蔽特性,可以得出水印被要求的相应的声压级。根据这些结果调制产生一个依赖于信号的不可觉察的水印。本算法允许在5秒钟的音频信号中嵌入25位信息。实验结果表明本文算法对于常见的信号处理攻击包括滤波、MP3压缩和添加噪声具有很好的健壮性。Audio watermarking offers a solution to data piracy and helps to protect the rights of the artists and copyright holders. In this paper, a novel audio watermarking scheme based on spread techniques that embeds a digital watermark within an audio signal using the instantaneous mean frequency (IMF) of the signal is presented. The algorithm aims to satisfy and maximize both imperceptibility and robustness of the watermark.The short-time Fourier transform of the original audio signal is used to estimate a weighted IMF of the signal. Based on the masking properties of the psychoacoustic model, we then derive the required sound pressure level of the watermark. From these results, modulation is performed to produce a signal-dependent watermark that is imperceptible. The proposed method allows 25bits to be embedded and recovered within a 5second sample of an audio signal. Experimental results have shown that our scheme is robust to common signal processing attacks including filtering,MP3 compression and noise addition.

关 键 词：数字音频水印 扩频 瞬时平均频率 时频 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]