DWT-SVD域全盲自嵌入鲁棒量化水印算法

引入自嵌入技术提出一种DWT-SVD域全盲鲁棒量化水印算法,只需借助攻击图像进行版权认证。对原始图像先进行DWT,将小波低频子带分成互不重叠的子块,对每个子块进行SVD,通过对比相邻两个子块最大奇异值的大小关系产生特征水印序列,然后将选定的自嵌入特征水印序列通过奇偶量化规则自嵌入原始图像小波低频子带每个子块的最大奇异值,最后进行SVD合成和IDWT产生含水印图像。算法具有良好的不可见性和安全性,并且通过结合自嵌入特征水印序列和盲提取认证水印序列达到全盲检测。实验结果表明,算法具有较强的抵抗添加高斯噪声、添加椒盐噪声、高斯低通滤波、中值滤波、剪切、JPEG压缩和混合攻击的鲁棒性。     

A new robust reference watermarking scheme based on DWT-SVD

This paper presents a new semi-blind reference watermarking scheme based on discrete wavelet transform(DWT) and singular value decomposition(SVD) for copyright protection and authenticity. We are using a gray scale logo image as watermark instead of randomly generated Gaussian noise type watermark. For watermark embedding, the original image is transformed into wavelet domain and a reference sub-image is formed using directive contrast and wavelet coefficients. We embed watermark into reference image by modifying the singular values of reference image using the singular values of the watermark. A reliable watermark extraction scheme is developed for the extraction of watermark from distorted image. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. We show that the proposed scheme also stands with the ambiguity attack also.     

A robust software watermarking for copyright protection

This paper advocates protecting software copyright through hiding watermarks in various data structures used by the code, e.g., B+-trees, R-trees, linked lists, etc. Prior proposals hide the watermarks in dummy data structures, e.g., linked lists and graphs that are created, solely for this reason, during the execution of the hosting software. This makes them vulnerable to subtractive attacks, because the attacker can remove the dummy data structures without altering the functionality or the semantic of the software program. We argue that hiding watermarks in one or more data structures that are used by the program would make the watermark more robust because disturbing the watermark would affect the semantic and the functionality of the underlying software. The challenge is that the insertion of the watermark should have a minimal effect on the operations and performance of the data structure.This paper proposes a novel method for watermarking R-tree data structure and its variants. The proposed watermarking technique does not change the values of the stored data objects. It takes advantage of the redundancy in the order of entries inside the R-tree nodes. Entries are arranged relative to a “secret” initial order, known only to the software owner, using a technique based on a numbering system that uses variable radix with factorial base. The addition of the watermark in the R-tree data structure does not affect the performance nor does it increase the size of the R-tree. The paper provides a detailed security analysis and performance evaluation to show that the embedded watermarks are robust and can withstand various types of attacks.     

A blind medical image watermarking: DWT-SVD based robust and secure approach for telemedicine applications

Multimedia Tools and Applications - In this paper, a blind image watermarking scheme based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. In this scheme,...     

A hybrid DWT-SVD copyright protection scheme based on k-means clustering and visual cryptography

In this paper, a novel copyright protection scheme that combines the discrete wavelet transform (DWT) and the singular value decomposition (SVD) is proposed. Instead of modifying the original host image to conceal a secret image, the proposed scheme first extracts the image features from the host image by applying the DWT and the SVD. The extracted features are then classified into two clusters by employing the k-means clustering technique, and a master share is generated using the clustering result. Finally, the master share is used together with a secret image to construct an ownership share according to a two-out-of-two visual cryptography (VC) technique. When rightful ownership needs to be determined, the secret image for ownership identification can be revealed by stacking the master share and the ownership share. Experimental results demonstrate that the proposed scheme can effectively resist several common attacks. In addition, the revealed watermark can be easily recognized by human eyes, even if the host image has undergone severe attacks.     

面向网关版权保护的抗几何攻击视频水印方法

为了解决网关视频的版权保护问题,提出了一种网关视频水印快速嵌入和提取方法。该方法在视频帧内,首先以近线性时间检测和挑选仿射协变区域,然后采用基于最小生成树的区域选择算法消除重叠区域,最后以线性时间在离散小波变换域内嵌入水印;在视频帧间,利用视频场景的连续性基于场景边界仿射协变区域预测场景内部仿射协变区域以达到整体加速的目的。攻击实验表明：对测试序列嵌入水印后,针对几何攻击和格式变换压缩攻击,水印检测准确率分别达到93%和83%以上。仿真实验表明：在400在线主机局域网内,该方法能在10帧以内成功阻断网关水印视频的传输。     

Robust copyright protection scheme for digital images using overlapping DCT and SVD

In this paper, a robust lossless copyright protection scheme, based on overlapping discrete cosine transform (DCT) and singular value decomposition (SVD), is presented. The original host image is separated into overlapping blocks, to which the DCT is applied. Direct current (DC) coefficients are extracted from the transformed blocks to form a DC-map. A series of random positions are selected on the map and SVD is performed to construct an ownership share which is used for copyright verification. Simulation results are carried out, demonstrating the robustness of the proposed scheme against different image-manipulation attacks.     

A self recoverable dual watermarking scheme for copyright protection and integrity verification

Dual watermarking implies embedding of robust as well as fragile watermarks into the same cover image. It facilitates integration of copyright protection and integrity verification into the same scheme. However, most of such existing state of art approaches either lacked the feature of tamper detection and original content recovery or provided an approximation using coarser block level approach. The proposed self recoverable dual watermarking scheme integrates all the aforementioned functionalities of copyright protection, tamper detection and recovery into one scheme. The scheme is independent of the order of embedding of robust and fragile watermarks as these are embedded in different regions of the cover image. It performs tamper detection and recovery, both at the pixel level. The scheme obtains recovery information for each 2×2 image block in just eight bits which are further encoded to only four bits via mapping table. This reduction in recovery bits allows efficient embedding of copyright information which is tested against comprehensive set of attacks. The scheme is found to be robust against noises, filtering, histogram equalization, rotation, jpeg compression, motion blur etc. Besides the normalized cross correlation value, the evaluation of the extracted copyright information is also being done using various objective error metrics based on mutual relation between pixels, their values and locations respectively. The imperceptibility and visual quality of the watermarked as well as recovered image is found to be satisfactorily high. Three major categories of images: natural, texture as well as satellite have been tested in the proposed scheme. Even minute alterations can be chalked out as the detection accuracy rate has been enumerated on pixel basis. The scheme can tolerate tampering ratios upto 50 percent though the visual quality of the recovered image deteriorates with increasing tampering ratio. Comparative results based on normalized cross correlation, probability of false acceptance, probability of false rejection and peak signal to noise ratio metrics validate the efficacy of the proposed scheme over other existing state of art approaches.     

An IWT based blind and robust image watermarking scheme using secret key matrix

Multimedia Tools and Applications - In this paper, the authors have proposed a binary watermark embedding approach for protecting the copyright ownership of the gray-scale images. The proposed...     

Blind robust watermarking schemes for copyright protection of 3D mesh objects

In this paper, two novel methods suitable for blind 3D mesh object watermarking applications are proposed. The first method is robust against 3D rotation, translation, and uniform scaling. The second one is robust against both geometric and mesh simplification attacks. A pseudorandom watermarking signal is cast in the 3D mesh object by deforming its vertices geometrically, without altering the vertex topology. Prior to watermark embedding and detection, the object is rotated and translated so that its center of mass and its principal component coincide with the origin and the z-axis of the Cartesian coordinate system. This geometrical transformation ensures watermark robustness to translation and rotation. Robustness to uniform scaling is achieved by restricting the vertex deformations to occur only along the r coordinate of the corresponding (r, /spl theta/, /spl phi/) spherical coordinate system. In the first method, a set of vertices that correspond to specific angles /spl theta/ is used for watermark embedding. In the second method, the samples of the watermark sequence are embedded in a set of vertices that correspond to a range of angles in the /spl theta/ domain in order to achieve robustness against mesh simplifications. Experimental results indicate the ability of the proposed method to deal with the aforementioned attacks.     

Cryptanalysis of Chu's DCT based watermarking scheme

In 2003, Chu proposed an oblivious watermarking algorithm by modifying the CKLS scheme proposed by Cox, Kilian, Leighton, and Shamoon in 1997, known as the CKLS scheme. In this correspondence, we report that the modification presented by Chu is susceptible to a suitably modified attack devised by Das and Maitra in 2004. In fact, the experimental results show that Chu's scheme is even weaker than the CKLS scheme in terms of our attack.     

一种改进的DWT-SVD域参考水印方案

针对一类SVD域图像水印方案存在过高虚警概率的问题,提出了一种改进的混合DWT和SVD的图像参考水印算法。算法先对载体图像进行[n]层的离散小波变换,然后随机选取第[n]层的部分或全部子带形成参考子带,并对参考子带进行SVD分解;将Arnold置乱处理后的水印嵌入到SVD分解后的奇异值矩阵中。实验表明,提出的算法具有较好的透明性和安全性;与其他方案相比,解决了虚警概率问题,且对于大部分的攻击,具有更好的鲁棒性能。     

A robust image watermarking scheme in DCT domain based on adaptive texture direction quantization

This paper proposes a novel robust image watermarking scheme in Discrete Cosine Transform (DCT) domain for active forensics. We investigate the relation between the positions and the modification magnitudes of DCT coefficients and directions of texture blocks. By exploring such relation, a direction-coefficient mapping is designed. First, the texture direction of each image block is estimated by Gabor filter. And then, according to the direction-coefficient mapping, one watermark bit is embedded into each block along its texture direction. Compared with existing schemes, the proposed method utilizes the direction features of texture blocks better . Therefore, the improvements in watermarked image quality and the robustness of watermark signal against image processing attacks are both achieved.

     

Metadata-based image watermarking for copyright protection

In this paper, we propose a practical application for copyright protection of images with watermarking. The EXIF metadata of images and error-control codes are integrated into our algorithm and corresponding applications. Application for robust watermarking is one of the major branches in digital rights management (DRM) systems and digital forensics. Here, we focus on the copyright protection for images taken by ordinary cameras. By use of robust watermarking, it generally alters selected coefficients of the contents to accomplish the embedding process. Should the received image be in question, the watermark embedded beforehand can be extracted to indicate the copyright owner of such an image. We consider not only the image contents itself, but we also employ the EXIF metadata, which serves as the role of watermark, to be integrated into our scheme to make copyright protection possible. Moreover, for enhancing the performance for copyright protection, channel coding is employed and better protection capability can be expected. Taking the manufacturer, camera model, date and time stamp, and other important information in the EXIF metadata into account, conventional watermarking techniques can be applied to ordinary pictures taken by ourselves, and watermarked images with good quality can be produced. Even when the marked image has been intentionally modified, the original EXIF with selected information can mostly be recovered from the channel decoding process. Simulation results present the effectiveness of such an implementation.     

基于DCT的自适应图像盲水印算法

数字水印技术是多媒体信息安全领域的一个重要的研究课题.提出了一种基于DCT域的盲水印算法,该算法将图像经DCT变换后进行8×8分块,然后将二值水印嵌入到每一个图像分块的中频系数中.在嵌入过程中利用每一块的中频系数的性质,自适应的确定嵌入强度,从而保证了所嵌入的水印对一些常用的图像处理操作具有很强的鲁棒性.实验结果验证了提出方法的有效性.     

DCT域音频水印透明健壮算法

提出一种新的基于离散余弦变换的数字音频水印算法。把音频信号划分为包含相同采样点的若干帧,每帧划分为若干节。对指定帧的第一节、第二两节实施DCT变换,将二者DCT中、高频系数的绝对值之和进行比较,结合水印序列为“0”或“1”,采取不改变、缩小及增加中、高频DCT系数的方法,在DCT系数中嵌入水印。实验证明,该算法具有较强的健壮性,较好的透明性,提取水印属盲水印提取,能经受重采样、重新量化、添加噪声、低通滤波、音频格式转换等常见信号处理及攻击。     

用于版权保护的图像数字水印方案

指出和论述了现有私有水印方案在版权保护方面存在的重要缺陷——不能防止伪造攻击;提出一个旨在防止伪造攻击的水印方案,并从理论上论证了其安全性。实验证明该方案具有可行性、鲁棒性和安全性。