共查询到20条相似文献,搜索用时 31 毫秒
1.
Xiang-Yang Wang Chang-Ying Cui 《Journal of Visual Communication and Image Representation》2008,19(5):334-342
In digital image watermarking, the watermark’s vulnerability to desynchronization attacks has long been a difficult problem. On the basis of support vector regression (SVR) theory and local image characteristics, a novel image watermarking scheme against desynchronization attacks by SVR revision is proposed in this paper. First, some pixels are randomly selected and the sum and variance of their neighboring pixels are calculated; second, the sum and variance are regarded as the training features and the pixel values as the training objective; third, the appropriate kernel function is chosen and trained, a SVR training model will be obtained. Finally, the sum and variance of all pixels’ neighboring pixels are selected as input vectors, the actual output can be obtained by using the well-trained SVR, and the digital watermark can be recovered by judging the output vector. Experimental results show that the proposed scheme is invisible and robust against common signals processing such as median filtering, sharpening, noise adding, and JPEG compression, etc., and robust against desynchronization attacks such as rotation, translation, scaling, row or column removal, shearing, local random bend, etc. 相似文献
2.
A relationship between quantization and watermarking rates in the presence of additive Gaussian attacks 总被引:2,自引:0,他引:2
Karakos D. Papamarcou A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(8):1970-1982
A system which embeds watermarks in n-dimensional Gaussian data and distributes them in compressed form is studied. The watermarked/compressed data have to satisfy a distortion constraint, and the watermark has to be recoverable in a private scenario (in which the original data are available at the watermark detector). The performance of the system in the presence of additive Gaussian attacks is considered, and the region of achievable quantization and watermarking rate pairs (R/sub Q/,R/sub W/) is established. Moreover, two surprising facts are demonstrated: (1) at low R/sub Q/, the maximum achievable R/sub W/ is the same as when there are no attacks; and (2) at high (but finite) R/sub Q/, the maximum achievable R/sub W/ is the same as when there is no compression (R/sub Q/=/spl infin/). Finally, the performance of related schemes is also discussed. 相似文献
3.
Jinwei Wang Shiguo Lian Leiming Yan Jin Han Yuxiang Wang 《Telecommunication Systems》2013,54(3):305-313
With the rapid development of Internet-based media consuming, the piracy issue becomes urgent, which makes copyright protection a hot research topic. There exist various watermarking methods that are regarded as potential solutions to copyright protection. However, most of watermarking methods have different properties, and the combinatorial method is expected to make use of different methods’ advantages and to get a good tradeoff. In this paper, a novel hybrid watermark embedding rule is proposed to select the general additive embedding rule or the special additive embedding rule securely. The selection is controlled by a secret key, and the watermark is embedded into the Discrete Wavelet Transform (DWT) domain. With respect to the hybrid embedding rule, the novel optimum and locally optimum hybrid additive decoder is proposed, which is based on the minimum Bayesian risk criterion. And simultaneously, the performance of the optimum hybrid decoder is theoretically analyzed, with the DWT coefficients modelled as the generalized Gaussian distribution. Furthermore, the security of the proposed hybrid watermarking scheme is proved higher than that of existing schemes. Finally, empirical experimental results are given to prove the validity of theoretical analysis. 相似文献
4.
In recent decades many articles have discussed the possibilities of chaos applied in communications. However, the vast majority consider in practical terms the ideal channel condition, which is clearly a restringing condition. Some papers show that when there is an additive noise, the synchronization error often disrupts communication. In this work, we present results of a comparison between synchronization error due to additive Gaussian noise when the transmitter and receiver are implemented by single or coupled maps. 相似文献
5.
Geometric attacks on image watermarking systems 总被引:2,自引:0,他引:2
Synchronization errors can lead to significant performance loss in image watermarking methods, as the geometric attacks in the Stirmark benchmark software show. The authors describe the most common types of geometric attacks and survey proposed solutions. 相似文献
6.
Cvetkovic Z. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(3):644-656
Representing signals using coarsely quantized coefficients of redundant expansions is an interesting source coding paradigm, the most important practical case of which is oversampled analog-to-digital (A/D) conversion. Signal reconstruction from quantized redundant expansions and the accuracy of such representations are problems which are not well understood and we study them in this paper for uniform scalar quantization in finite-dimensional spaces. To give a more global perspective, we first present an analysis of the resilience of redundant expansions to degradation by additive noise in general, and then focus on the effects of uniform scalar quantization. The accuracy of signal representations obtained by applying uniform scalar quantization to coefficients of redundant expansions, measured as the mean-squared Euclidean norm of the reconstruction error, has been previously shown to be lower-bounded by an 1/r/sup 2/ expression. We establish some general conditions under which the 1/r/sup 2/ accuracy can actually be attained, and under those conditions prove a 1/r/sup 2/ upper error bound. For a particular kind of structured expansions, which includes many popular frame classes, we propose reconstruction algorithms which attain the 1/r/sup 2/ accuracy at low numerical complexity. These structured expansions, moreover, facilitate efficient encoding of quantized coefficients in a manner which requires only a logarithmic bit-rate increase in redundancy, resulting in an exponential error decay in the bit rate. Results presented in this paper are immediately applicable to oversampled A/D conversion of periodic bandlimited signals. 相似文献
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8.
Yu. A. Sidorkina V. V. Sizykh B. I. Shakhtarin V. A. Shevtsev 《Journal of Communications Technology and Electronics》2016,61(7):807-816
The Markovian mathematical model of the Kostas phase-locked loop subjected to the simultaneous actions of additive harmonic interferences and a white Gaussian noise, which are described by stochastic differential equations involving the influence of the low-pass filters of the control loop on the useful pulsed signal shape, is discussed. The statistical characteristics of the error signal are analyzed in the linear approximation. 相似文献
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10.
Counterfeiting attacks on oblivious block-wise independentinvisible watermarking schemes 总被引:26,自引:0,他引:26
We describe a class of attacks on certain block-based oblivious watermarking schemes. We show that oblivious watermarking techniques that embed information into a host image in a block-wise independent fashion are vulnerable to a counterfeiting attack. Specifically, given a watermarked image, one can forge the watermark it contains into another image without knowing the secret key used for watermark insertion and in some cases even without explicitly knowing the watermark. We demonstrate successful implementations of this attack on a few watermarking techniques that have been proposed in the literature. We also describe a possible solution to this problem of block-wise independence that makes our attack computationally intractable. 相似文献
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12.
一种基于统计量化的抗几何攻击图像水印算法 总被引:3,自引:0,他引:3
依据图像受到几何攻击时亮度值统计特性不变原理提出了一种基于统计量化的抗几何攻击图像水印算法。用二值序列作为水印,水印嵌入时,首先选取一段亮度值范围,然后根据一定的步长将其划分为小区间,每一水印位对应一区间,最后对亮度值进行量化,使每个区间的像素都被量化到一个亮度值上。水印提取时,首先统计每个亮度值的像素个数,然后按照嵌入时的方法选取亮度范围并且划分区间,从每个区间提取一位水印信息。实验表明,这种方法对图像缩放、旋转和剪切等几何攻击有很强的鲁棒性,对中值滤波、噪声等常规攻击也具有较强鲁棒性。 相似文献
13.
Denoising and copy attacks resilient watermarking by exploitingprior knowledge at detector 总被引:2,自引:0,他引:2
Watermarking with both oblivious detection and high robustness capabilities is still a challenging problem. In this paper, we tackle the aforementioned problem. One easy way to achieve blind detection is to use denoising for filtering out the hidden watermark, which can be utilized to create either a false positive (copy attack) or false negative (denoising and remodulation attack). Our basic design methodology is to exploit prior knowledge available at the detector side and then use it to design a "nonblind" embedder. We prove that the proposed scheme can resist two famous watermark estimation-based attacks, which have successfully cracked many existing watermarking schemes. False negative and false positive analyses are conducted to verify the performance of our scheme. The experimental results show that the new method is indeed powerful. 相似文献
14.
The homomorphic cryptosystems create a great opportunity for secure signal processing (SSP). Watermarking in the encrypted domain provides a promising solution to the security of watermarking. However, the robust performance of the watermarking scheme in the encrypted domain should be carefully considered. In this paper, we propose a robust watermarking scheme in the encrypted domain, which protects the original images from the third party embedders. The hybrid discrete wavelet transform (DWT) and discrete cosine transform (DCT) based method improves the robust performance of the encrypted domain watermarking scheme. The watermark extraction can be performed on both the plaintext and the encrypted domains. We also give an estimation of the expanding factor after watermark embedding in the encrypted domain. At last, we discuss the watermark attacks that are available in the encrypted domain. Taking Haar wavelet transform for example, we conduct the experiments on the visual quality and the robustness of our watermarking scheme, which demonstrate that the entire performance is satisfactory. 相似文献
15.
Serdean C.V. Ambroze M.A. Tomlinson M. Wade J.G. 《Vision, Image and Signal Processing, IEE Proceedings -》2003,150(1):51-58
The paper describes a high-capacity blind video watermarking system invariant to geometrical attacks such as shift, rotation, scaling and cropping. A spatial domain reference watermark is used to obtain invariance to geometric attacks by employing image registration techniques to determine and invert the attacks. A second, high-capacity watermark, which carries the data payload, is embedded in the wavelet domain according to a human visual system model. This is protected by a state-of-the-art error correction code (turbo code). For a false detection probability of 10/sup -8/, the proposed system is invariant to scaling up to 180%, rotation up to 70/spl deg/, and arbitrary aspect ratio changes up to 200% on both axes. Furthermore, the system is virtually invariant to any shifting, cropping, or combined shifting and cropping. The system is also robust to MPEG2 compression, even when combined with shifting and cropping. 相似文献
16.
Lei-Da Li Bao-Long Guo 《AEUE-International Journal of Electronics and Communications》2009,63(2):123-131
Watermark robustness to geometric attacks is still a challenging research field. In this paper, a novel robust image watermarking scheme is proposed for resisting such attacks. Watermark synchronization is first achieved by local invariant regions which can be generated using scale normalization and image feature points. The watermark is embedded into all the local regions repeatedly in spatial domain. During embedding, each circular region is first divided into homocentric cirque regions. Then the watermark bits are embedded by quantizing each cirque region into an “odd” or “even” region using odd–even quantization. In the decoder, an odd–even detector (OED) is designed to extract the watermark from the distorted image directly. Localized embedding achieves good invisibility and repeated insertion enhances watermark robustness. Simulation results show that the proposed scheme is robust to both geometric attacks and traditional signal processing attacks. 相似文献
17.
McKellips A.L. Verdu S. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1997,43(4):1256-1264
Additive-noise channels with binary inputs and zero-threshold detection are considered. We study worst case noise under the criterion of maximum error probability with constraints on both power and divergence with respect to a given symmetric nominal noise distribution. Particular attention is focused on the cases of a) Gaussian nominal distributions and b) asymptotic increase in worst case error probability when the divergence tolerance tends to zero 相似文献
18.
针对传统离散小波变换(DWT)水印算法不能较好地抵抗几何攻击的缺点,提出了一种基于离散小波变换(DWT)和奇异值分解(SVD)相结合的彩色图像水印新算法。首先对原始彩色载体图像进行RGB三基色分解,然后进行离散小波变换,再选取四个子块的四分之一重构成新子块,并进行二次离散小波变换,最后对其低频部分进行奇异值分解嵌入水印信息,得到嵌入水印的彩色图像。实验结果表明,该算法能够较好地抵抗诸如高斯噪声、椒盐噪声、压缩等常规攻击,并对大角度旋转、任意角度旋转、剪切加旋转等几何攻击也表现出了较强的鲁棒性,其总体性能明显优于传统的DWT水印算法。 相似文献
19.
基于SIFT特征点和交比值的水印图像抗攻击算法 总被引:1,自引:0,他引:1
为提高数字水印图像对常规信号和复杂几何攻击的抵抗能力,利用SIFT(scale invariant feature transform)特征点的稳健性和交比值不变特性,提出了一种数字图像顽健水印算法。首先,在原图像经过NSCT(nonsubsampled contourlet transform)变换后的低频子带系数中提取SIFT特征点并对其进行优化筛选,从中确定满足“近凸正四边形” 的系数区域作为水印嵌入的局部区域,然后利用事先设定好的一些交比值在各局部区域中确定要嵌入水印的具体系数,最后利用奇偶量化调制方法嵌入水印信息。与传统算法相比,在提取水印信息时无需对含水印图像进行几何逆变换。实验结果表明,该算法对常规信号处理及多种几何攻击具有较强的抵抗能力和顽健性。 相似文献
20.
Asymptotically optimal detection for additive watermarking in the DCT and DWT domains 总被引:10,自引:0,他引:10
Most of the watermarking schemes that have been proposed until now employ a correlation detector (matched filter). The current paper proposes a new detector scheme that can be applied in the case of additive watermarking in the DCT (discrete cosine transform) or DWT (discrete wavelet transform) domain. Certain properties of the probability density function of the coefficients in these domains are exploited. Thus, an asymptotically optimal detector is constructed based on well known results of the detection theory. Experimental results prove the superiority of the proposed detector over the correlation detector. 相似文献