一种可盲检测的多功能音频水印算法

为了使数字水印实现多种功能,提出了一种能在同一音频信号中同时嵌入多个水印的新方法.首先,载体音频信号被分隔成指定长度的帧,并且所有成员水印被编码成一个混合水印.然后,利用回声隐藏技术将混合水印中的二进制比特嵌入到音频信号帧中.水印提取不需要原始音频信号.为了提高水印算法的提取正确率和抵御常规信号处理的鲁棒性,功率倒谱的自相关被用于检测携带水印的音频信号帧中的回声延时以提取出混合水印,并且相应的解码算法被用于分离成员水印.计算机仿真结果表明所提出的水印算法对常规的信号处理,如Mp3压缩、重采样、重量化、低通滤波以及白噪声具有很强的鲁棒性.     

基于回声延时的数字音频水印技术

提出一种将数字水印在时间域上嵌入到数字音频信号中的方法，该方法利用回声将水印隐藏起来，其水印算法简单，能够保证好的音频信号质量。     

Multipurpose audio watermarking algorithm

To make audio watermarking accomplish both copyright protection and content authentication with localization, a novel multipurpose audio watermarking scheme is proposed in this paper. The zero-watermarking idea is introduced into the design of robust watermarking algorithm to ensure the transparency and to avoid the interference between the robust watermark and the semi-fragile watermark. The property of natural audio that the VQ indices of DWT-DCT coefficients among neighboring frames tend to be very similar is utilized to extract essential feature from the host audio, which is then used for watermark extraction. And, the chaotic mapping based semi-fragile watermark is embedded in the detail wavelet coefficients based on the instantaneous mixing model of the independent component analysis （ICA） system. Both the robust and semi-fragile watermarks can be extracted blindly and the semi-fragile watermarking algorithm can localize the tampering accurately. Simulation results demonstrate the effectiveness of our algorithm in terms of transparency, security, robustness and tampering localization ability.     

一种基于视觉模型的DCT数字水印算法

如何解决不可见性和鲁棒性之间的矛盾一直是数字水印算法的关键问题。提出了一种基于视觉模型的DCT域盲水印算法，该方法通过对视觉模型的亮度遮蔽特性和对比度遮蔽特性的研究和使用，优化了水印的嵌入位置和水印的嵌入强度，确保了水印信号能够在合适的嵌入位置上以尽可能大的嵌入强度嵌入，使得水印保持了较好不可见性的同时，其鲁棒性也得到了一定的提高。实验结果表明，该水印算法对噪音、裁剪以及压缩攻击具有较强的鲁棒性，算法是有效的。     

Science Letters:A new asymmetric watermarking scheme based on a real fractional DCT-I transform

INTRODUCTIONDue to the ease of transmitting digital data and copying without loss of quality, the unauthorized distribution of digital multimedia contents has be-come easy and popular. Digital watermarking is the most promising technique to protect the copyright of digital multimedia contents (Cox et al., 2001). Most of the proposed watermarking schemes are symmetric, in which keys for watermark detecting are identical to those for watermark embedding. Therefore, symmet-ric watermarking s…     

基于CPLD的数字音频系统设计

多通道音频控制器是数字音响系统必不可少的组成部分 ,它可以通过程序对输入功放的的多路音频信号进行选择 ,对音量和音调进行调节 ,并以数字方式直观显示控制结果。另外还具有话筒输入信号放大以及放大后与原音混合实现伴唱的功能。为简化所设计的数字电路 ,本系统使用大规模可编程逻辑控制器CPLD作为系统核心 ,将程序编译后下载到CPLD器件中 ,实现设计所要求的功能     

A new asymmetric watermarking scheme based on a real fractional DCT-I transform

A new asymmetric watermarking scheme is proposed in this letter. In the proposed scheme, a secret real fractional DCT-I transform and a primitive watermark are employed to generate an asymmetric watermark. The secret watermark for embedding is derived from the primitive watermark, and is embedded in the large fractional DCT-I transformation coefficients of a cover signal. The asymmetric detection procedure is performed using a correlation test. Simulation results showed that the asymmetric detection is reliable, and that the scheme can provide minimum security.     

Using the Wavelet as the Private Key for Encrypting the Watermark

Watermarking is an effective approach to the copyright protection of digital media such as audio,image,and video.By inspriation from cryptography and considering the immensity of the set of all possible wvaelets,it is presented that in wavelet domain watermarking,the associated wavelet can be considered as the private key for encrypting the wavtermark so as to enhance the security of the embedded mark.This idea is partly supported by the fact that from computational complexity viewpoint.It is very time-consuming to search over the immense set of all candidate wavelets for the right one if no a priori knowledge is known about it .To verify our proposal,the standard image“Lena”is first watermarked in a specific wavelet domain,the watermark recovery experiments are then conducted in the wavelet domain for a set of wavelets with the one used for mark embedded in it ,separately.It follows from the experimetal results that the mark can be recovered only in the right wavelet domain,which jusstifies the suggestion.     

基于小波包分解的自适应盲脆弱水印算法

提出了基于图像内容自嵌入功能的脆弱水印算法．算法的新颖之处在于能区分图像内容、水印还是两者同时被篡改,由原图像高7位的一级小波低频系数量化得压缩图像,转换成二进制作为水印,混沌置乱加密后嵌入到原图像的LSB．认证时,由认证图像高7位制作的水印与提取水印的差值来确定图像是否遭到窜改,可定位篡改位置．实验结果表明：与Y-M算法相比峰值信噪比提高了5个dB,与WONG算法相比峰值信噪比提高了3个dB,实现了盲检测,而且该算法能够检测常见的攻击如噪声、几何剪切、滤波等．     

鲁棒性数字图像水印算法研究

为了有效保护多媒体信息的版权,研究利用离散余弦变换的算法对整个数字水印图像进行数字变换,将水印加载在中低频分量上以保护原多媒体信息,对数字水印图像的嵌入、提取和攻击进行鲁棒性测试,试验表明该方法不仅可以从攻击后的图像中完整提取水印,而且水印的鲁棒性及抗攻击性较好,可经受一定程度的有损信号处理和一般的数字几何变换,有较强的推广价值.     

基于模运算的数字水印算法研究

介绍了数字水印的分类，提出了一种基于模运算的数字水印算法。该算法具有很好的性能：水印隐藏的效果好，凭借人类的视觉系统无法看出与原图像的差别；可以有效地抵抗JPEG等压缩编码的破坏；可以依靠部分图像检测水印，在图像受到损坏的情况下，仍可以检测到水印信息；检测水印时受到口令的限制，不知道口令的人无法正确恢复水印；检到水印时不需要原始图像。     

Music in Audio‐visual Materials

Music has an important place in theatre productions and in instructional audiovisual material. Why is this, what functions has the music and what are its effects? Literature on music in audio‐visual material and on its design is very scarce. The concept of music and its characteristics are described in some detail, indicating that music per se has no referential meaning. The theory is presented that music has an emotional effect that can be manipulated by the developer of audio‐visual material. On the other hand, music offers resources for commenting and structuring audio‐visual material.     

基于混沌和离散余弦变换的数字水印算法

提出了基于混沌和离散余弦变换的数字水印算法,该算法是将混沌映射序列作为水印信息,并在载体图像的离散余弦变换域较大幅度值上嵌入排序后的水印信息,而在水印提取时,再利用原图像、水印图像和密钥进行水印重构。Matlab仿真实验结果表明,该算法在保证水印不可感知性的同时,对添加噪声、高斯低通滤波、中值滤波、裁剪、旋转等常见信号处理攻击具有较强的稳健性。     

基于数字水印的多媒体教学资源保护

将数字水印用于数字化音视频产品的版权保护,弥补了传统的数据加密方式的不足,成为数字版权管理的有效手段。传统加密技术在数字版权保护中存在的问题是,数据一旦被解密,数字内容就可以非法复制和传播。因此提倡将版权信息作为水印加入数字作品的多媒体教学资源保护策略。一     

基于混沌加密和HVS在数字水印算法中的应用

针对混沌系统和人类视觉特性改进一种鲁棒性数字水印算法。原始图像经过离散小波变换提取子带系数,二值灰度数字水印图像信号在嵌入时经过Logistic混沌映射预处理,结合人眼视觉特性,水印图像嵌入到重要的子带系数中,实验证明该方案对常见的图像处理如噪声、剪切、旋转等攻击具有很好的鲁棒性。     

基于多值序列模运算的混合变换域水印

提出一种基于多值序列模运算的新的变换域公开水印算法，将图像的特征序列量化成可忍受的极限能量多值水印信号随机嵌入到图像的DCT、DWT混合变换域中，通过对特征序列量化结果和提取水印的相关性进行统计，得出水印判定结果。     

培养音乐内心听觉能力的心理学探讨

培养音乐内心听觉能力，是一个从听觉注意——听觉记忆——听觉思维——听觉预感的完整的心理过程。在感知音乐作品之前要注意培养良好听觉注意心理品质；在“有理解地听”的基础上。培养音乐记忆能力；在理解音乐作品基础上进行听觉分析，培养音乐思维能力；在培养“听觉预感”的基础上。培养良好的“乐感”。     

基于混沌置乱的DWT域语音水印算法的研究

作为信息隐藏技术中的数字水印技术是信息时代的一个热门研究课题。语音水印技术由于受到人的听觉特性的限制,使得传统数字水印技术在实现上有一定难度。研究并实现了一种基于混沌置乱技术引入传统的DWT域语音水印算法,该算法可以实现向宿主语音信号嵌入具有特定意义的数字水印,且由于引入了混沌置乱技术极大地提高了水印的安全性和鲁棒性,并同时具有易于提取和高透明性的特点。     

数字水印技术综述

简单介绍了数字水印技术的概念、原理和特点,根据水印所附载体不同,将数字水印分为图像水印、音频水印、视频水印、文本水印、网格水印和软件水印,并描述了其原理和各种不同的实现方法.最后介绍了数字水印技术目前在各个领域的应用,并指出数字水印技术的发展方向.     

一种空间域的可见水印

1　Introduction　Indigitallibrariesthereistheneedtodevelopef fectivetechniquesappliedtotheimagesto protectcopyright.Digitalwatermarkthatisvisible ,robustanddifficulttoremoveisthereforeaddedtoimagestodiscouragecopyrightinfringement[1] .Thoughvisiblewatermarkingreducesthecommercialvalueofthehost information ,itdoesnothoweverattractpiratesthuspreventingtheimagefromtheft[1 6 ] .Manyre searcheshavebeencarriedoutondigitalwatermark ing .Fewerstudies,however ,havebeenreportedonvisiblewatermarkingasco…