共查询到19条相似文献,搜索用时 93 毫秒
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基于BP神经网络和SNR的自适应音频水印算法 总被引:3,自引:3,他引:0
提出一种基于BP神经网络和信噪比(SNR)的自适应音频水印算法。通过修改音频分抽样后子音频帧小波变换近似分量均值的方法嵌入水印。水印嵌入强度由期望的SNR值确定,可避免反复实验或者由经验数据确定水印强度。水印的提取以子音频抽样帧小波变换近似分量均值为BP神经网络的输入,以神经网络的输出作为提取的水印。经过模板训练的BP神经网络能有效的恢复嵌入到音频中的水印数据,实现了水印的盲检测。实验结果表明,本文提出的水印算法具有较好的鲁棒性和不可听性。 相似文献
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针对现有音频内容取证算法采用二值图像作为辨识水印所带来的安全隐患,以及基于音频内容或特征生成的辨识水印稳定性不高,易被常规信号处理操作淹没的问题,提出了一种新的基于时域统计特征的音频内容取证算法。通过对音频信号时域统计平均值进行非均匀量化生成辨识水印。理论和实验结果表明通过该方法生成的辨识水印能够抵抗常规信号处理操作,稳定性高。生成的辨识水印存储于认证中心,组建辨识水印库。对音频内容进行取证时,将由该音频生成的辨识水印与从水印库中提取的对应辨识水印进行比对,即可对待取证音频的真实性、完整性进行鉴定。该取证方法操作简便,对不同类型音频均能实现篡改定位,对常规音频信号处理操作的鲁棒性高,有效扩大了基于内容音频取证算法的应用范围。 相似文献
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提出了一种基于声学心理模型和小波包变换的的音频水印算法,适用于立体声音频信号和单声道音频信号。对于立体声音频信号,在左右声道加入不同的水印信号;对于单声道音频信号,在奇偶帧加入不同的水印信号。左声道水印通过源信号包络与一个只有版权拥有者持有的随机序列加权生成水印信号,并且通过对得出信号进行小波包和声学心理模型分析控制水印信号的强度;右声道水印信号为幅度限制在可听门限的白噪声,用来控制检测门限。得到的水印信号在时域嵌入,水印的检测无需原文件。该方法能够将检测门限控制在事先设定的范围内,具有较好的隐秘性;嵌入的水印信号能够抵抗时域的切割、加噪攻击和一般的音频变换算法。 相似文献
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文中提出了一种基于均值量化的小波域自同步数字音频水印算法。该算法是一种盲水印算法,水印提取不需要原始音频信号的参与。算法设计中运用了均值量化的策略,音频信号小波分解后,在低频系数中隐藏水印信息;引入了同步信号的思想,利用同步信号定位水印隐藏位置。实验表明,该算法具有较强的鲁棒性、抗攻击性、抗裁剪性。 相似文献
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为保证DCT域水印的鲁棒性,研究水印信号的嵌入位置非常必要.对音频载体,尽管有许多文献提出将水印嵌在中频系数或对听觉效果重要的系数上,但始终缺乏一个统一的方法.本文在DCT噪声信号模型研究的基础上,提出了一种新的音频水印嵌入位置选择策略和一个应用该策略的自适应音频水印算法.通过定义DCT系数的噪声敏感度,建立了水印嵌入位置和嵌入水印后的音频信号的听觉感知性之间的关系,根据音频水印的不可听性的要求选择最优的嵌入位置,然后调节水印强度来满足鲁棒性的要求,从而最大程度地保持音频水印的不可听性和鲁棒性,为解决音频水印嵌入过程中不可听性和鲁棒性之间的矛盾提供了一种策略.应用该策略,本文提出了一个自适应音频水印算法.实验证实了算法的鲁棒性. 相似文献
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介绍了一种基于小波变换的同步盲水印算法,该算法首先将二值水印图像置乱后经过降维操作转换成为一维序列.并用m序列作同步信号与水印序列一起组成嵌入序列,嵌入到音频信号的小波变换域低频系数中.在水印检测时不需要原始音频信号参与.实验表明,该算法具有较好的鲁棒性. 相似文献
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Designing an optimal audio watermarking system is an open difficult issue since its two basic performance measures, i.e., imperceptibility and robustness, are conflicting with each other. So, an optimal audio watermarking scheme needs to optimally balance both imperceptibility and robustness. In order to realize such an optimal watermarking system, by considering the balance as an optimization problem, we propose an optimal audio watermarking scheme using genetic optimization with variable-length mechanism in this paper. The presented genetic optimization procedure can automatically determine optimal embedding parameters for each audio frame of an audio signal. Specially, employed variable-length mechanism can effectively search most suitable positions for watermark embedding, including suitable audio frames and their AC coefficients. By dint of the genetic optimization with variable-length mechanism, proposed audio watermarking scheme can not only guarantee good quality of watermarked audio signal but also effectively improve its robustness. Experimental results show that proposed watermarking scheme has good imperceptibility and high capability against common signal processing and some desynchronization attacks. 相似文献
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一种新的扩频音频水印算法 总被引:3,自引:2,他引:3
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。 相似文献
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Digital watermark technology is now drawing attention as a new method of protecting digital content from unauthorized copying. This paper presents a novel audio watermarking algorithm to protect against unauthorized copying of digital audio. The proposed watermarking scheme includes a psychoacoustic model of MPEG audio coding to ensure that the watermarking does not affect the quality of the original sound. After embedding the watermark, our scheme extracts copyright information without access to the original signal by using a whitening procedure for linear prediction filtering before correlation. Experimental results show that our watermarking scheme is robust against common signal processing attacks and it introduces no audible distortion after watermark insertion. 相似文献
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介绍了一种基于DSP的数字音频处理系统.后级音频功放电路以DPPC2006为核心,选用H桥输出方式,提高了电源的使用效率,方案具有很强的灵活性,可以采用各种快速音频处理算法实现各种声场效果. 相似文献
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A perceptual audio coder, in which each audio segment is
adaptively analyzed using either a sinusoidal or an optimum wavelet basis
according to the time-varying characteristics of the audio signals, has been
constructed. The basis optimization is achieved by a novel switched filter
bank scheme, which switches between a uniform filter bank structure
(discrete cosine transform) and a non-uniform filter bank structure
(discrete wavelet transform). A major artifact of the International
ISO/Moving Pictures Experts Group (MPEG) audio coding standard (MPEG-I
layers 1 and 2) known as pre-echo distortion which uses a uniform filter bank structure for
audio signal analysis, is almost eliminated in the proposed coder. A
perceptual masking model implemented using a high-resolution wavelet packet
filter bank with 27 subbands, closely mimicking the critical bands
of the human auditory system, is employed in this audio coder. The resulting
scheme is a variable bit-rate audio coder, which provides compression ratios
comparable to MPEG-I layers 1 and 2 with almost transparent quality. 相似文献