基于音频统计特性的数字水印嵌入算法

结合数字音频时频域统计特性及同步码技术, 提出了一种可有效抵抗去同步攻击的混合域数字音频水印嵌入算法. 该算法首先结合数字水印与同步码(大小), 对原始音频载体进行分段处理, 并将每个音频数据段分割成两部分用于嵌入同步码与水印信息; 然后利用时间域音频样本统计特性, 将同步码信息嵌入到音频样本的统计均值上; 最后根据频率域小波系数统计特性, 将数字水印嵌入到低频小波系数的平均值内.     

一种新的SVM数字音频水印嵌入算法

为了取得鲁棒性与不可感知性的良好平衡,提出一种新的SVM数字音频水印嵌入算法.该算法以回归型支持向量机(SVR)理论及同步码技术为基础,首先结合数字音频内容,选取稳定的能量、过零率作为特征向量并获得SVR训练模型,然后利用SVR训练模型自适应确定嵌入位置,最后采纳量化调制策略,分别在空间域和频率域内将同步码和数字水印嵌入到音频载体内.仿真实验表明,本文算法不仅具有较好的不可感知性,而且对诸如叠加噪声、重新采样、重新量化、低通滤波、MP3压缩、随机剪切等攻击均具有较好的鲁棒性.     

基于重心的抗同步攻击的音频水印算法

抗同步攻击是音频水印领域公开的难题. 相对重心是音频的一个稳定的全局特征量, 对 TSM (Time scale modification)等同步攻击不敏感. 本文提出一种基于相对重心的抗同步攻击的音频水印算法,提出的算法通过量化音频的相对重心生成水印, 生成的水印由混沌序列加密后以量化的方法嵌入载体音频三级小波近似分量均值中. 为了降低同步攻击后同步位置的连续偏移, 水印嵌入提取过程采用了均匀分帧的方法. 实验结果表明提出的算法能抵抗常规信号处理操作, 同时 能抵抗20%的TSM操作(包含音调不变TSM和重采样操作)和 1/10的抖动操作, 有很好的鲁棒性.     

基于经验模式分解的音频水印算法

针对传统基于经验模式分解(EMD)的音频水印算法鲁棒性不强的问题,提出一种基于固有模态函数(IMF)极值的盲音频水印算法.首先对音频信号进行分帧,每个音频帧经过EMD后得到IMF; 接着利用均匀量化的方法将水印信息和同步码嵌入到最后一个IMF的极值中.所提算法的数据嵌入率是46.9~50.3 b/s,且携水印音频保持了原始音频的感知质量.对携水印音频进行加噪、MP3压缩、重新采样、滤波、剪切和重采样攻击后,提取出的水印信息变化不大,算法鲁棒性较好.与时间域和小波域算法相比,提出的算法在保证高数据嵌入率的同时,可以抵抗32 kb/s的MP3压缩攻击.     

基于音频特征的抗去同步攻击数字水印算法

抗去同步攻击的强鲁棒数字音频水印方法研究是一项富有挑战性的工作.本文结合数字音频自身特征,提出了一种基于音频内容的抗去同步攻击数字水印算法.该算法首先根据数字音频的局部能量特征,从原始载体中提取出稳定的特征点;然后以音频特征点为标识,确定用于水印嵌入的候选音频段;最后采纳量化调制策略,将数字水印嵌入到音频载体内.进行数字水印检测时,系统通过分析音频内容提取特征点,再以特征点为标识提取水印信息,水印检测无需原始音频信号参与.仿真实验结果表明,本文算法不仅具有较好的不可感知性,而且对常规信号处理(MP3压缩、低通滤波、添加噪声等)和去同步攻击(随机剪切、幅度缩放、时间延展、抖动等)均具有较好的鲁棒性.     

基于小波域的均值量化数字音频水印算法

提出了一种均值量化的小波域数字音频水印算法。均值量化可以减少攻击对水印的影响,算法选择合适的小波基对音频信号进行小波分解,对其中的中、低频系数进行均值量化,嵌入水印,水印提取过程不需要原始音频信号。实验结果表明,与一般水印量化算法相比,该算法对MP3、重量化、重采样、低通滤波和噪声干扰等信息处理型攻击具有更好的鲁棒性。     

一种基于小波变换的同步音频水印技术

提出了一种小波域下基于量化系数的自同步鲁棒性音频数字水印方案,该算法首先将视觉可辩的二值水印图像降维成一维序列,再用密钥将水印序列伪随机排序,然后插入m序列作为同步码,最后对数字音频信号进行分段H层DWT变换,通过量化系数的方法把预处理后的水印序列重复多次嵌入到DWT变换后的低频分量中.提取水印信息时无需原始音频信号的辅助,实现了水印的盲检测.实验结果表明水印是不可察觉的,经过低通滤波、mp3压缩、重抽样、噪声干扰等操作后水印系统仍具有强的鲁棒性,并且能比较有效地抗击裁剪攻击.     

奇偶量化的抗同步攻击音频水印方案

提出一种基于奇偶量化的音频水印算法,算法具有如下特点：（1）在音频信号的时间域上检索满足条件的同步信号区,同步信号区是一段具有一定长度且能量较大的音频信号;这种时间域上的同步检索具有较高的效率;（2）水印图像划分成若干块,把每一个水印分块及其分块编号嵌入在一个同步信号区的小波变换低频系数上,水印图像划分成分块循环嵌入到检索到的同步信号区,当含水印的音频信号被裁剪后,可以确保在其他音频段提取出正确的水印分块;（3）水印检测不需要参考原始音频信号,是一种盲检测水印算法。仿真实验证明了算法对常见的音频信号处理具有较好的鲁棒性和不可感知性,对同步攻击、抖动攻击具有很好的鲁棒性。     

频谱嫡特征识别的抗去同步鲁棒性MP3水印算法

提出了一种鲁棒的、将离散余弦系数(MDCT)频谱嫡修正为隐含同步码的压缩域水印,实现了基于音频内容的自同步。算法结合MP3编解码原理对解压后的音频数据分块实施重复嵌入,并根据心理声学模型的掩蔽效应选取合适的嵌入位置,通过处理低频DWT系数完成嵌入。将非压缩域音频信号重新压缩为含有水印信息的MP3码流。 在解码过程中通过频谱墒关系序列定位水印提取位置,实现了水印的盲提取。仿真实验结果表明,算法在保证水印不可感知性的情况下,对抵抗去同步攻击以及Stirmark软件的常见攻击具有良好的鲁棒性。     

基于感兴趣区域的图像水印嵌入算法研究

鉴于现有绝大多数图像水印方案将载体图像看作整个场景,并未考虑载体图像自身的结构特征及人们感兴趣的视觉目标区域,本文提出了一种基于感兴趣区(ROI)的小波域图像水印嵌入算法.该算法首先结合人眼视觉感知特性,在小波变换域内利用k-均值聚类提取出感兴趣区域;然后对感兴趣区域进行小波变换,并结合图像局部相关性对小波系数进行自适应的量化调制,将水印信息嵌入到感兴趣区域的低频子带内.仿真实验表明,所提出的水印嵌入算法不仅具有较好的透明性,而且对JPEG压缩、叠加噪声、锐化等常规图像处理操作具有较好的鲁棒性.特别地,该算法能够有效抵御恶意剪切、目标移动、替换背景等攻击,而且可以实现盲检测.     

A robust digital audio watermarking based on statistics characteristics

In digital audio watermarking, the watermark's vulnerability to desynchronization attacks has long been a difficult problem. According to the audio statistics characteristics and synchronization code technique, a new robust audio watermarking scheme against desynchronization attacks is proposed in this paper. Firstly, the original digital audio is segmented and then each audio segment is cut into two parts. Secondly, with the spatial watermarking technique, the synchronization code is embedded into the statistics average value of audio samples in the first part. Finally, the second part of audio segment is cut into audio sections, the DWT is performed on the audio sections, and the watermark bit is embedded into the statistics average value of low frequency components. Experimental results show that the proposed scheme is inaudible and robust against common signals processing, including MP3 compression, low-pass filtering, noise addition, and equalization, etc. Moreover, it also survives several desynchronization attacks, such as random cropping, amplitude variation, pitch shifting, time-scale modification, and jittering, etc.     

A pseudo-Zernike moment based audio watermarking scheme robust against desynchronization attacks

Desynchronization attack is known as one of the most difficult attacks to resist, for it can desynchronize the location of the watermark and hence causes incorrect watermark detection. It is a challenging work to design a robust audio watermarking scheme against desynchronization attacks. Based on pseudo-Zernike moment and synchronization code, we propose a new digital audio watermarking algorithm with good auditory quality and reasonable resistance toward desynchronization attacks in this paper. Firstly, the origin digital audio is segmented and then each segment is cut into two parts. Secondly, with the spatial watermarking technique, synchronization code is embedded into the statistics average value of audio samples in the first part. And then, map 1D digital audio signal in the second part into 2D form, and calculate its pseudo-Zernike moments. Finally, the watermark bit is embedded into the average value of modulus of the low-order pseudo-Zernike moments. Meanwhile combining the two adjacent synchronization code searching technology, the algorithm can extract the watermark without the help from the origin digital audio signal. Simulation results show that the proposed watermarking scheme is not only inaudible and robust against common signals processing such as MP3 compression, noise addition, resampling, re-quantization, etc., but also robust against the desynchronization attacks such as random cropping, amplitude variation, pitch shifting, jittering, etc.     

A new adaptive digital audio watermarking based on support vector machine

It is a challenging work to design a robust digital audio watermarking scheme against desynchronization attacks. On the basis of support vector machines (SVMs), a new robust digital audio watermarking algorithm against desynchronization attacks is proposed in this paper, and in this the audio statistics characteristics and synchronization code are utilized. Firstly, the optimal embedding positions are located adaptively by using the SVM theory. Secondly, the 16-bit Barker code is chosen as synchronization mark and embedded into the digital audio by modifying the statistics average value of several samples. Finally, the digital watermark are embedded into the statistics average value of low-frequency components in wavelet domain by making full use of auditory masking. Experimental results show that the proposed scheme is inaudible and robust against common signal processing such as MP3 compression, low-pass filtering, noise addition, equalization, etc., and is robust against desynchronization attacks such as random cropping, amplitude variation, pitch shifting, time-scale modification, jittering, etc.     

A robust digital audio watermarking scheme using wavelet moment invariance

It is a challenging work to design a robust audio watermarking scheme against various attacks. Wavelet moment invariances are new features combining the moment invariant features and the wavelet features, and they have some excellent characteristics, such as the ability to capture local information, robustness against common signal processing, and the linear relationship between a signal and its wavelet moments etc. Based on wavelet moment and synchronization code, we propose a new digital audio watermarking algorithm with good auditory quality and reasonable resistance against most attacks in this paper. Firstly, the origin digital audio is segmented and then each segment is cut into two parts. Secondly, with the spatial watermarking technique, synchronization code is embedded into the statistics average value of audio samples in the first part. And then, map 1D digital audio signal in the second part into 2D form, and calculate its wavelet moments. Finally, the watermark bit is embedded into the average value of modulus of the low-order wavelet moments. Meanwhile combining the two adjacent synchronization code searching technology, the algorithm can extract the watermark without the help from the origin digital audio signal. Simulation results show that the proposed watermarking scheme is not only inaudible and robust against common signals processing such as MP3 compression, noise addition, resampling, and re-quantization etc., but also robust against the desynchronization attacks such as random cropping, amplitude variation, pitch shifting, and jittering etc.     

High payload multi-channel dual audio watermarking algorithm based on discrete wavelet transform and singular value decomposition

Digital watermarking technology is concerned with solving the problem of copyright protection, data authentication, content identification, distribution, and duplication of the digital media due to the great developments in computers and Internet technology. Recently, protection of digital audio signals has attracted the attention of researchers. This paper proposes a new audio watermarking scheme based on discrete wavelet transform (DWT), singular value decomposition (SVD), and quantization index modulation (QIM) with a synchronization code embedded with two encrypted watermark images or logos inserted into a stereo audio signal. In this algorithm, the original audio signal is split into blocks, and each block is decomposed with a two-level DWT, and then the approximate low-frequency sub-band coefficients are decomposed by SVD transform to obtain a diagonal matrix. The prepared watermarking and synchronization code bit stream is embedded into the diagonal matrix using QIM. After that, we perform inverse singular value decomposition (ISVD) and inverse discrete wavelet transform (IDWT) to obtain the watermarked audio signal. The watermark can be blindly extracted without knowledge of the original audio signal. Experimental results show that the transparency and imperceptibility of the proposed algorithm is satisfied, and that robustness is strong against popular audio signal processing attacks. High watermarking payload is achieved through the proposed scheme.     

一种新的用于音频认证数字水印算法

为确保数字音频数据感知意义上的完整性,提出了一种新的音频认证水印算法。该算法把原始音频分帧,每帧分为两节,在第一节时域中嵌入同步码,将第二节进行DCT变换,计算邻帧关系向量,并将其作为水印信息嵌入其他帧第二节的DCT中频系数。认证时,计算邻帧关系误差,据事先设定的阈值来判断音频是否被窜改,若遭受窜改,可进行窜改定位。仿真实验表明,该算法在无原始水印参与的情况下,不仅可以实现音频媒体的完整性认证,而且窜改定位准确。     

基于小波域低频系数的自适应数字音频水印算法

水印嵌入强度是影响水印鲁棒性的重要因素。该文设计了一种基于小波域低频系数自适应数字音频水印算法,利用混沌序列对水印加密,再将原始音频信号分段,对每段音频信号进行小波变换,嵌入强度由每段低频系数与低频系数最大值的比值自适应的选取,最后将水印嵌入到各段的低频部分。实验结果表明,水印在抵抗各种通用的音频处理和攻击(如高斯噪声、MP3压缩、重采样等)方面具有良好的鲁棒性。     

A source coding scheme for authenticating audio signal with capability of self-recovery and anti-synchronization counterfeiting attack

Authenticating the veracity and integrity of digital media content is the most important application of fragile watermarking technique. Recently, fragile watermarking schemes for digital audio signals are developed to not only detect the malicious falsification, but also recover the tampered audio content. However, they are fragile against synchronization counterfeiting attack, which greatly narrows the applicability of audio watermarking schemes. In this paper, a novel source coding scheme for authenticating audio signal based on set partitioning in hierarchical trees (SPIHT) encoding and chaotic dynamical system with capability of self-recovery and anti-synchronization counterfeiting attack is proposed. For self-recovery feature, the compressed version of audio signal generated by SPIHT source coding and protected against maliciously tampering by repeated coding is embedded into the original audio signal. Besides, for robustness against synchronization counterfeiting attack feature, based on the position and content of audio section, check bits are generated by Hash algorithm and chaotic sequence, and taken as part of fragile watermark. Simulation results show the self-embedding audio authentication scheme is recoverable with proper audio quality, and it has capability against synchronization counterfeiting attack.