具备上下文依赖及鲁棒性的视频水印算法

数字水印技术可用于内容的鉴定及防止伪造，被看作是对已发布内容避免其受到未经授权的复用的重要技术。所有权信息以水印的方式嵌入至数字内容中，从而能够提供版权保护、所有权声明、数码内容完整性核查及其在遭受攻击时提供版权侵害的证据，因而水印技术成为构造数字媒体版权备选的方案。本文介绍了水印方法与有信编码与嵌入的关联性，设计了一个有效的方法，使用码字子集来代表预插入的0或1数据位。此外，还提出了一个码字生成方案，能控制码间距，从而保证了水印的鲁棒性与信号的保真度。通过比较测试可以看出，我们提出的方法在视频压缩方面具备出色的稳健性。     

VRML animated model watermarking scheme using geometry and interpolator nodes

Distinct from image and video watermarking, a watermarking scheme for 3D animation content is required in the 3D industry market for various applications. This paper develops a watermarking scheme for copyright protection and authentication of 3D animation content. A 3D animated model generally has a hierarchical structure with a number of transform nodes of a geometry node and an interpolator node for the timeline in contrast to a 3D polygon mesh model. The proposed scheme embeds not only a robust watermark into the geometry node for copyright protection but also a fragile watermark into the position and orientation interpolators for content authentication. We named the former “robust geometry watermarking” and the latter “fragile interpolator watermarking”. The proposed scheme performs the two watermarking schemes independently to realize simultaneously robust and fragile watermarked 3D animated model. Experimental results confirm that a watermark embedded by geometry watermarking robust to many attacks from commercial 3D editing tools while a watermark embedded by interpolator watermarking fragile to the same attacks.     

基于图像特征的鲁棒性数字水印算法

为了同时实现图像版权保护和图像内容的真伪性鉴定,提出了一种基于数字图像特征的鲁棒性数字水印算法。先利用Hessian变换提取宿主图像的特征区域,并根据每个特征区域内各个像素点的局部方向,将用于版权保护的水印信息嵌入到这些特征区域中。同时,向图像中除特征区域之外的区域嵌入用于图像内容真伪鉴定的脆弱性水印。水印提取过程是水印嵌入的逆过程,在不需要原始图像的情况下实现了版权水印和内容鉴定水印的提取。实验表明,该算法能抵杭大多数的移除攻击等几何篡改,对篡改发生的位置定位效果良好。     

基于标记矢量量化的多重音频数字水印算法

提出一种基于矢量量化和DCT变换的多重音频数字水印算法.该算法将鲁棒水印和脆弱水印分别嵌入到载体音频信号中,同时完成版权保护和音频内容完整性认证的功能.鲁棒水印在进行码字标记的矢量量化过程中嵌入到DCT中频系数中,脆弱水印采用索引约束的方法嵌入到DCT高频系数中.鲁棒水印和脆弱水印都能实现盲提取.实验结果表明,本算法引...     

A multipurpose audio watermarking algorithm with synchronization and encryption

We propose a new multipurpose audio watermarking scheme in which two complementary watermarks are used.For audio copyright protection,the watermark data with copyright information or signature are first encrypted by Arnold transformation.Then the watermark data are inserted in the low frequency largest significant discrete cosine transform(DCT) coefficients to obtain robustness performance.For audio authentication,a chaotic signal is inserted in the high frequency insignificant DCT coefficients to detect tampered regions.Furthermore,the synchronization code is embedded in the audio statistical characteristics to resist desynchronization attacks.Experimental results show that our proposed method can not only obtain satisfactory detection and tampered location,but also achieve imperceptibility and robustness to common signal processing attacks,such as cropping,shifting,and time scale modification(TSM).Comparison results show that our method outperforms some existing methods.     

一种基于自适应量化的半脆弱图像水印算法

提出了一种基于自适应量化的半脆弱图像水印嵌入方案，能够在不参考原始载体的情况下对数字图像同时进行版权保护和内容认证．该半脆弱水印嵌入方案具有以下特点：（1）抽取并利用了原数字水印的特征信息（作为辅助水印）；（2）采纳了基于人眼视觉特性的自适应量化策略；（3）数字水印信息的提取不需要原始载体图像；（4）采用整型提升小波变换，克服了小波域水印算法普遍存在的舍入误差问题；（5）能够同时进行版权保护与内容认证，并可确定篡改发生区域．仿真实验表明：该小波域水印嵌入方案不仅对JPEG压缩、叠加噪声、平滑滤波等常规图像处理具有较好鲁棒性。而且能够对替换等恶意图像篡改做出报警反应，同时其误检率与漏检率等关键技术指标均优于现有半脆弱水印嵌入算法．     

用于版权保护与内容认证的半脆弱音频水印算法

提出了一种可同时用于版权保护与内容认证的半脆弱数字音频盲水印算法. 该算法具有以下特点: 1)结合音频自身特性, 不仅能够自适应划分音频数据段, 而且能够智能调节水印嵌入强度, 增强了数字音频水印的鲁棒性; 2)能够同时进行数字音频的版权保护与内容认证, 并可大致确定篡改发生区域. 仿真实验表明, 文中算法不仅具有较好的不可感知性, 而且对常规处理具有较好的鲁棒性, 同时能够对替换等恶意篡改作出报警并确定被篡改位置.     

基于可信赖第三方的鲁棒性的图像水印方案

图像水印技术主要是用来保护图像的版权。提出了一个鲁棒性的基于可信赖第三方的图像水印方案，这种方法有两大优点。方案中的水印和原图像是同一种类型，例如灰度级图像。方案满足水印技术的要求。由于引入了可信赖第三方，用户无法觉察和破坏图像中的水印。它能够抵抗各种图像改变算法的攻击，包括滤波、有损压缩和旋转等。     

结合视觉密码和离散小波变换的栅格地理数据双重水印

目的 在栅格地理数据的使用过程中,为防止数据被破坏或被篡改,需要加强对数据完整性的检验;为防止数据被恶意传播,需要加强对数据版权信息的保护。双重水印技术可以同时完成这两项任务。方法 利用基于异或的（2,2）-视觉密码方案VCS（visual cryptography scheme）和离散小波变换DWT（discrete wavelet transform）,对数字栅格地理数据嵌入双重水印,使用半脆弱性水印作为第1重水印进行完整性检验,水印信息依据DWT变换后高频系数中水平分量之间的大小关系嵌入;使用零水印作为第2重水印进行版权保护,提取DWT变换后经低频子带奇异值分解的特征值生成特征份,利用基于异或的（2,2）-VCS,根据特征份和水印信息生成版权份。结果 为验证算法的有效性,对具体的栅格地理数据进行实验分析。结果表明,本文算法中第1重水印能够正确区分偶然攻击和恶意破坏,对含水印的栅格地理数据进行质量因子为90、80、70、60、50的JPEG压缩后,提取出完整性水印的归一化相关系数NC（normalized correlation）值分别是1、0.996、0.987、0.9513、0.949,在定位裁剪攻击时,能准确地定位到篡改的位置,对于定位替换攻击时,能定位到篡改的大致位置;第2重水印具有良好的视觉效果和较强的鲁棒性,对含水印的栅格地理数据进行滤波攻击、JPEG压缩、裁剪攻击、缩放攻击等性能测试,提取出版权水印的NC值优于其他方案。结论 论文基于异或的（2,2）-VCS和DWT提出的栅格地理数据双重水印算法,在实现数据完整性检验的同时达到了版权保护的目的。     

基于YCbCr彩色空间的彩色图象水印新方法

随着计算机网络和多媒体技术的发展,数字水印技术正逐渐成为多媒体版权保护的一种有效途径。数字水印处理的目的在于将秘密的个人信息隐含于数字多媒体信号中,以保护其知识产权或证明其真实可靠性,提出了一种基于彩色空间的彩色图象水印处理方法。输入的彩色图象首先由通常的RGB空间变换到YCbCr彩色空间,在YCbCr空间中给出了四种嵌入水印的方案和相应的水印检测算法,最后,实验证明了算法的有效性。     

一种基于空间域的彩色图像水印算法

多媒体数字水印可以为媒体提供所有权证明和知识产权保护,或用来验证媒体的内容是否真实可信。该文提出一种基于空间域的彩色图像水印算法,利用不同处理和攻击对YUV彩色空间中亮度通道Y和色度通道UV的破坏力不同的特性,根据图像亮度和纹理的不同,对亮度和色度通道分别嵌入不同强度的水印信息。在水印检测算法中,为提高水印对图像增强处理的稳健性,对待检图像和原始图像进行了归正。实验结果表明该方法能很好地抗击JEPG压缩的攻击,同时对中值滤波等低通滤波器、亮度/对比度等图像增强、锐化、平滑、栅栏及噪声干扰等攻击也具有较好的稳健性。     

复合式的多功能数字水印算法

提出了一种鲁棒性数字水印和脆弱性数字水印相结合的复合式水印算法,具有较好的双重保护性能,即鲁棒性数字水印用于版权认证方面和脆弱性数字水印用于图像内容的保护.首先,在原始载体图像的DCT中频域上嵌入不可见水印;其次,再根据LSB算法在空域自适应地嵌入脆弱性数字水印.实验结果表明,该方法不可见性好,对一般的图像处理和攻击,如JPEG压缩、滤波、加噪声、旋转、缩放等都有良好的鲁棒性,同时还能对图像中细微的篡改进行有效精确的定位,并且作为一种盲水印算法有着良好的安全性.     

一种改进的混编视频水印方案

提出了一种具有鲁棒性和脆弱性的改进混编视频水印方案:将鲁棒性和脆弱性水印分别嵌入到vc}宏块的中频交流系数和运动矢量的水平分量中,实现了秘密信息及验证信息在视频中的隐藏,具有版权保护和视频完整性认证的能力。实验结果表明,与C}. Qiu等提出的混编视频水印方案相比,该方案在鲁棒性水印嵌入时,码率增幅平均降低6%,有更好的抗攻击能力;脆弱性水印对攻击的敏感性更高。     

Fragile watermarking for authenticating 3-D polygonal meshes

Designing a powerful fragile watermarking technique for authenticating three-dimensional (3-D) polygonal meshes is a very difficult task. Yeo and Yeung were first to propose a fragile watermarking method to perform authentication of 3-D polygonal meshes. Although their method can authenticate the integrity of 3-D polygonal meshes, it cannot be used for localization of changes. In addition, it is unable to distinguish malicious attacks from incidental data processings. In this paper, we trade off the causality problem in Yeo and Yeung's method for a new fragile watermarking scheme. The proposed scheme can not only achieve localization of malicious modifications in visual inspection, but also is immune to certain incidental data processings (such as quantization of vertex coordinates and vertex reordering). During the process of watermark embedding, a local mesh parameterization approach is employed to perturb the coordinates of invalid vertices while cautiously maintaining the visual appearance of the original model. Since the proposed embedding method is independent of the order of vertices, the hidden watermark is immune to some attacks, such as vertex reordering. In addition, the proposed method can be used to perform region-based tampering detection. The experimental results have shown that the proposed fragile watermarking scheme is indeed powerful.     

A novel DCT domain CRT-based watermarking scheme for image authentication surviving JPEG compression

Digital watermarking techniques have been proposed for copyright protection and authentication of multimedia data. In this paper, we propose a novel Chinese Remainder Theorem (CRT)-based technique for digital watermarking in the Discrete Cosine Transform (DCT) domain that is robust to several common attacks. We compared the performance of the proposed technique with recently proposed Singular Value Decomposition (SVD)-based and spatial CRT-based watermarking schemes. Experimental results have shown that the proposed technique successfully makes the watermark perceptually invisible and has better robustness to common image manipulation techniques such as JPEG compression, brightening and sharpening effects compared to the spatial domain-based CRT scheme. The proposed scheme is able to achieve a Tamper Assessment Function (TAF) value of less than 10% when the watermarked image undergoes JPEG compression between a range of 50 to 70%, where as, the spatial CRT-based scheme produce TAF value of more than 35% and the SVD-based scheme produces TAF value between 10 to 40% depending on the host image, for the same range of compression. When the watermark capacity is doubled, the proposed technique is still able to maintain imperceptibility and low TAF values, for most of the attacks.     

An efficient wavelet-tree-based watermarking method

This paper proposes a blind watermarking scheme based on wavelet tree quantization for copyright protection. In such a quantization scheme, there exists a large significant difference while embedding a watermark bit 1 and a watermark bit 0; it then does not require any original image or watermark during watermark extraction process. As a result, the watermarked images look lossless in comparison with the original ones, and the proposed method can effectively resist common image processing attacks; especially for JPEG compression and low-pass filtering. Moreover, by designing an adaptive threshold value in the extraction process, our method is more robust for resisting common attacks such as median filtering, average filtering, and Gaussian noise. Experimental results show that the watermarked image looks visually identical to the original, and the watermark can be effectively extracted.     

Hierarchical Watermarking of Semiregular Meshes Based on Wavelet Transform

This paper presents a hierarchical watermarking framework for semiregular meshes. Three blind watermarks are inserted in a semiregular mesh with different purposes: a geometrically robust watermark for copyright protection, a high-capacity watermark for carrying a large amount of auxiliary information, and a fragile watermark for content authentication. The proposed framework is based on wavelet transform of the semiregular mesh. More precisely, the three watermarks are inserted in different appropriate resolution levels obtained by wavelet decomposition of the mesh: the robust watermark is inserted by modifying the norms of the wavelet coefficient vectors associated with the lowest resolution level; the fragile watermark is embedded in the high resolution level obtained just after one wavelet decomposition by modifying the orientations and norms of the wavelet coefficient vectors; the high-capacity watermark is inserted in one or several intermediate levels by considering groups of wavelet coefficient vector norms as watermarking primitives. Experimental results demonstrate the effectiveness of the proposed framework: the robust watermark is able to resist all common geometric attacks even with a relatively strong amplitude; the fragile watermark is robust to content-preserving operations, while being sensitive to other attacks of which it can also provide the precise location; the payload of the high-capacity watermark increases rapidly along with the number of watermarking primitives.      

抵抗多种攻击的视频水印新方案

随着多媒体技术的发展,数字视频的版权保护变得越来越重要.为了设计一种更加实用的数字视频水印,提出了集成多种技术的、对多种攻击鲁棒的自适应、盲检测视频水印新算法.首先,利用Arnold置乱技术将水印置乱,并进行Turbo编码,以提高其安全性;然后,根据视频的特征,即归纳的频率敏感性、色度敏感性、运动敏感性、纹理敏感性和亮度敏感性选取关键帧,并运用分块技术将关键帧进行3维分块;再进行3维小波分解,选中低频区域作为嵌入域;此外,为了抵抗旋转、缩放攻击,采用了一种新方法,即用Zernike矩提取视频的旋转、缩放不变信息;最后采用盲检测技术提取水印.通过对典型视频数据的攻击和测试,得出了水印的鲁棒性指标.结果表明,本文水印适合多种内容特点的视频,能够抵抗目前常见的各类攻击,具有一定的实用价值.     

基于数字水印的图像版权保护和内容认证方案

实现版权保护和内容认证是数字水印的两个最主要功能,而现有同时实现这两个功能的数字水印方案并不完美。提出了结合人类视觉系统在图像的绿色分量中嵌入版权信息,实现版权保护,在蓝色分量中嵌入二值图像,实现内容认证。实验证明该方法透明性好,版权保护水印对JPEG压缩、高斯噪声等攻击抵抗力强,内容认证水印能有效地刻画攻击和定位篡改。     

基于几何不变性的图像水印

数字水印是信息隐藏技术的一个重要方向,它在版权保护和认证等方面应用的非常广泛。正因为此,水印对攻击具有鲁棒性是很重要的。本文首先介绍水印技术现状及其安全方面的一些研究,然后详细研究图像水印中的几何不变性水印。并着重研究基于不变矩的不变水印以及图像归一化技术。其中,本文所针对的对水印的攻击是几何攻击,包括缩放、翻转和旋转等基本的几何操作。