基于色彩分量相关性的彩色图像可擦除水印算法*

通过研究自然图像色彩分量之间的相关性,提出一种在彩色图像中嵌入可擦除水印的新方法。该方法在图像分块的基础上,利用色彩分量之间的相关性在每一图像块中嵌入两位水印,水印信号是用有意义的水印图像经混沌序列调制生成的二值序列,嵌入位置由绿色分量的平均值和密钥决定,具有非常好的安全性和易碎性,水印的提取和擦除不需要原始图像。实验表明,该方法嵌入的水印不可见性好,擦除水印的图像与原始图像完全一致,适合于图像的精确认证。     

一种合谋安全的数据库指纹编码与盗版追踪算法

在将数据库作为软件产品发行的应用场合,需要有相应的安全机制对叛逆用户的盗版行为进行约束.本文提出了一种基于数字指纹的关系数据库盗版追踪解决方案.以混沌二值序列将版权水印与用户指纹组合而成数据库指纹,在密钥的控制下嵌入数据库.基于混沌二值序列的随机性进行指纹提取与叛逆追踪.方案具有较高的合谋安全性,同时降低了指纹检测与叛逆追踪的运算复杂度.文中描述了数据库指纹编码与嵌入、指纹检测与提取算法,分析了算法的鲁棒性与叛逆追踪能力,并进行了实验验证.     

一种基于非对称水印的图像认证改进算法研究

提出一种基于非对称水印的图像认证改进算法,算法中将经过BCH编码和混沌序列调制的认证信息作为水印,利用所有者私钥嵌入图像DCT域,嵌入过程根据DCT块的可视噪声阈值(JND)控制,用户可以利用公钥从水印图像中提取认证信息,但无法从公钥中获取任何私钥信息,从而无法破坏或删除水印.实验结果表明:改进算法中水印图像的PSNR值相比原算法增大4.4dB,并且对常见的基于图像处理的攻击,鲁棒性大大提高.     

一种自适应灰度级数字水印改进算法

灰度级水印图像,因信息量大而影响嵌入质量与稳定性.提出一种基于多级小波变换新的嵌入策略,使得嵌入灰度级水印图像的数据量更少,水印稳定性更强,并且具有良好的抗剪切、擦除、噪音、滤波与JPEG压缩失真的能力.在嵌入过程中,采用公钥密码体制加密,使得水印安全性得到进一步提高.     

一种基于网络安全传输的指纹身份认证水印嵌入新算法

通过用户端和客户端的两次握手解决了水印图像网络传输的安全性，抵抗了重放攻击，提高了自动指纹识别系统的可信度。提出基于人眼视觉系统和小波多尺度分解原理，使合法用户指纹特征信息作为水印自适应嵌入宿主图像新颖算法，保证指纹信息的安全性和完整性。     

基于双分量差值扩展的彩色图像可擦除水印*

针对Tian算法中过度利用差值造成含印图像质量下降严重的问题,提出了基于双分量差值扩展的彩色图像可擦除水印算法。该算法将差值扩展量分散到四个灰度值中,含印图像质量明显提高。实验表明,该方法嵌入的水印不可见性好,擦除水印的图像与原始图像完全相同,适合于图像的精确认证和窜改定位。     

基于回归型支持向量机的医学图像可视可逆水印算法

随着医学影像技术的发展,医学图像成为医生诊断患者病情的主要依据,为了给患者提供更为准确的诊断和最佳的治疗方案,医学图像共享和专家远程诊断成为重要的诊疗手段。未被保护的医学图像在传输过程中易受到攻击或恶意篡改,为有效保护医学图像信息的完整性并限制未授权用户的使用,提出了一种基于回归型支持向量机的医学图像可视可逆水印算法。该算法首先将可视水印嵌入医学图像中;其次利用回归型支持向量机对水印图像的像素值进行预测,并计算出预测误差,利用纹理度等级自适应确定合适的亮度调节阈值,根据阈值生成一幅全局定位图,将全局定位图加入到原始图像中,以增强算法的鲁棒性;最后利用全局定位图和预测误差之间的相互关系生成一个可视可逆的水印,从而对医学图像进行加密保护。实验结果表明,所提可视可逆算法不仅可应用于传统医学图像,还首次应用于弥散加权图像,且该算法具有较好的鲁棒性和可逆性,能有效避免像素点溢出问题,实现可逆水印的正确提取,提取水印后的图像与原始图像没有任何差异。在水印信息未知的情况下,可视可逆水印去除困难,该特性可有效保护患者信息的完整性和医学图像的权威性。     

一种有关DWT与SVD相结合的多功能水印新方案

提出了基于DWT和SVD相结合的多功能数字水印算法,主要用于图像版权保护和图像认证.该算法选取奇异值量化的方法分别嵌入鲁棒性水印和脆弱水印,鲁棒性水印主要用于适用于图像版权保护,脆弱水印主要用于检测图像被篡改的位置.在该方案中,采用分块双重置乱技术用于水印图像隐藏的预处理,以保障水印的安全性.实验结果表明,该算法不仅对JPEG有损压缩、中值滤波、剪切、低通滤波等各种图像降级处理有很强的稳健性,同时对图像篡改位置进行精确的检测,以抵制抗擦除或伪造易损水印的攻击.     

基于移动设备的匿名可追踪版权保护协议

提出了基于移动设备的匿名可追踪的版权管理协议。首先,它使用不断变换的临时身份来代替用户的真实 身份,使其他人不可能跟踪到用户,它关注用户动态,具有匿名性;其次,使用一次口令申请一个水印的方法来抵杭假 冒攻击;再次,采用单向哈希函数的认证方法对用户身份、数字内容进行验证;协议中的一些计算由可信中心完成,以 减少移动用户的计算量,提高效率。另外在数字产品中嵌入版权水印和指纹水印,当发现非法副本时,它可以对叛逆 者进行追踪,具有可追踪性。分析表明,该协议是安全有效的。     

可视密码学的Contourlet域图像水印

将可视密码学引入到水印的预处理中,提出了一种Contourlet域的安全性较高的图像水印算法。该算法首先根据可视密码理论将水印信息隐藏到一定数目的图片中,选取其中任一图片作为水印,然后对载体图像进行分块,通过聚类找出适合嵌入水印的块,并进行Contourlet变换,在变换系数的最大奇异值上嵌入水印。水印提取时只需用特定数目的图片对提取出的信息进行叠加,其过程无需大量计算和密码学知识。实验表明,该算法还具有抵抗噪声、滤波、JPEG压缩等常规攻击和抗剪裁等功能。     

Adaptive removable visible watermarking technique using dual watermarking for digital color images

This paper proposes a removable visible watermarking system based on a dual watermark technique and blind removal. A visible watermark pattern is embedded in the cosine discrete transform (DCT) domain, taking into consideration the texture and luminance features of the watermark and host images to create a visible watermarked image. To prevent illegal visible watermark removal, the original watermark is embedded in an invisible manner in the visible watermarked image by employing the Quantization Index Modulation-Dither Modulation (QIM-DM) technique, thus ensuring that the original watermark cannot be obtained by malicious attacks. The visible watermark removal process is carried out using only the correct user’s keys, without the need for additional information, such as the original watermark or the original host image, which allows a high-quality image to be obtained; however, if the user’s keys used in the removal process are wrong, the visible watermarked image suffers higher distortion in its content, even in non-visible watermarked regions. The experimental results show that the proposed system outperforms previous related works in terms of blind removal, preservation of the quality of the unmarked recovered image, and higher visual degradation of the content in the recovered image if an illegal removal attempt is performed.     

Robust blind watermarking approach against the compression for fingerprint image using 2D-DCT

This article presents a recent blind and robust fingerprint image watermarking scheme based on a two-dimensional discrete cosine transform (2D-DCT). The main focus is to compress the fingerprint image watermarked data for the purpose of reducing the volume of storage or sending over the network. The fingerprint features might be affected by the embedded watermark, compression of fingerprint images and the sending across network, thereby leading to various sets of features or watermark data. In order to address this goal in a differential way, the watermark sequence bit two sub-vectors were utilized. The two sub-vectors were achieved by the two-dimensional discrete cosine transform of the host image. Throughout the extraction stage, the essential distinction between the corresponding sub-vectors of the watermarked fingerprint image resulted explicitly in an embedded watermark sequence. The advantage of the proposed method is that it can develop a new simple blind and robust watermarking scheme by 2D-DCT frequency domain on the whole image. Accomplished results relative to other reliable compression schemes showed that the proposed scheme has greater or equivalent robustness to common image processing and geometric attacks, such as cropping, resizing, and rotation. To extract watermark data, the initial fingerprint image was not necessary. The proposed study was tested using 80 fingerprint images from 10 persons, for each from CASIA-FingerprintV5 and FVC2002 fingerprint databases. Eight fingerprint images for each individual were set as the format at which the watermark was embedded in each one.

     

基于JPEG 2000实时量化水印和指纹识别的身份认证系统

提出了新的JPEG2000实时量化水印算法,并将其用于改进的基于指纹识别和数字水印的银行养老金发放系统。系统客户端,量化水印在JPEG2000压缩过程中实时嵌入指纹图像,压缩比特流传送到服务端;系统服务端,水印在JPEG2000解压缩过程中实时提取,使用解压缩的指纹图像和水印进行身份认证。实验表明典型指纹图像压缩到1/4~1/20的时候,嵌入的水印能够无损提取,指纹图像虽不能完全恢复但识别率没有明显降低。因而在低网络带宽条件下,新系统有更好的交互性能,在电子商务中有很好的应用前景。     

On Security of Compressed Gray Scale Image Using Joint Encryption and Data Hiding

ABSTRACT

This paper proposes a novel scheme that integrates quality access control and tracking of illicit distribution of digital image(s) in a single platform. The goal is achieved by (1) modulating some of the valuable Discrete Cosine Transform (DCT) coefficients of the compressed data followed by (2) embedding a binary watermark (fingerprint) as tracking information using Quantization Index Modulation (QIM). The data modulation process serves the purpose of access control so that an unauthorized user is unable to enjoy proper visual quality. On the other hand, embedded watermark tracks illicit distribution. The coefficients to be modulated are selected pseudo randomly using a secret key (K). Before embedding, the watermark is encoded by applying convolution coding that reliably identifies colluder(s) involved in time varying (intelligent) collusion operation. Simulation results have shown the validity of the above claims without affecting compatibility with standard JPEG coding scheme.     

Robust watermarking of fingerprint images

This paper introduces two spatial methods in order to embed watermark data into fingerprint images, without corrupting their features. The first method inserts watermark data after feature extraction, thus preventing watermarking of regions used for fingerprint classification. The method utilizes an image adaptive strength adjustment technique which results in watermarks with low visibility. The second method introduces a feature adaptive watermarking technique for fingerprints, thus applicable before feature extraction. For both of the methods, decoding does not require original fingerprint image. Unlike most of the published spatial watermarking methods, the proposed methods provide high decoding accuracy for fingerprint images. High data hiding and decoding performance for color images is also observed.     

彩色图像可见水印的网络算法

在对可见教字水印算法以及.NET Framework GDI+技术的研究基础上,提出一种彩色图像可见水印的网络实现算法.该算法将彩色图像从RGB空间转换到HSI空间后,根据载体图像信息计算出嵌入强度大小,在空域中嵌入可见水印以实现彩色图像的版权保护功能.实验结果表明:嵌入的水印对原始彩色图像的影响较小并且很难被去除,为图像提供较好的保护,且嵌入图像大小、位置均可调整,实用性好.     

一种用于版权通知和保护的遥感图像水印算法

本文提出了一种用于版权通知和保护的遥感图像数字水印算法。算法以灰度图像作为可见水印及不可见水印,首先在空域中对遥感图像进行可见水印的嵌入,以实现版权通知功能;然后对图像进行小波变换,在小波域中嵌入不可见水印,以实现版权保护功能。水印提取采用与嵌入相同的逆过程,得到置乱的水印图像,采用一种新的Arnold反变换方法对水印进行反置乱,最终得到嵌入的水印图像。实验表明,嵌入的可见水印很难去除,不可见水印对图像的质量影响很小,并对常规处理具有较好的鲁棒性。     

Service-oriented grid computing system for digital rights management (GC-DRM)

Service-oriented computing and applications have recently gained significant attention since they provide new service infrastructure and development of service-oriented technology. Under such trend and ubiquitous computing requirement, grid computing is becoming popular in scientific and enterprise computing due to its flexible deployment and implementation. In this paper, we proposed a service-oriented digital rights management (DRM) platform based on grid computing (called GC-DRM) which is in the compliance of Grid Portal standards by using porlet. The platform integrates Globus Toolkit 4 and Condor 6.9.2 and uses web 2.0 to construct the web-based user interface for providing job submission, control, management, monitor for DRM services. GC-DRM can provide different categories of services which include watermark embedding and extraction, image scrambling, visible watermark embedding, image tamper-detection and recovery. In addition, GC-DRM has been applied to analyze the robustness of digital watermark by filter bank selection and the performance can be improved in the aspect of speedup, stability and processing time compared with NaradaBrokering based Computing Power Services (NB-CPS) and Web Services based Computing Power Service (WS-CPS). Therefore, GC-DRM can be concluded as a superior service-oriented computing which provides the user friendly environment with efficient DRM service performance based on grid computing architecture.     

基于图像指纹的数字图像水印检测方法

数字水印是近年来出现的一种新的数字媒体产品版权保护技术，然而在实际应用情况下，带有水印的图像不可避免地会受到一些如图像滤波、图像增强、图像锐化和图像压缩等无意攻击及合谋攻击、混淆攻击、削去攻击等恶意攻击。数字图像水印的仿射变换攻击破坏水印检测器与水印信号的同步达到攻击的目的，是一种有效的水印攻击方法。利用图像指纹恢复经仿射变换的水印图像，使水印检测器与水印同步以达到有效检测水印的目的。实验表明，使用该方法能较好地恢复图像，有效地同步水印检测器与水印信号，从而使水印对仿射变换攻击具有鲁棒性。