共查询到17条相似文献,搜索用时 78 毫秒
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检测时无需原始图像的盲数字水印是实用的数字作品版权保护系统的变换系数的拉普拉斯分布模型,推导并实现了一种有效的盲图像水印符号相关检测器.通过计算渐进相对效率证明了该检测器具有较高的检测效率.实验结果表明该检测器具有良好的鲁棒性. 相似文献
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一种几何攻击下的数字图像水印检测方法 总被引:2,自引:0,他引:2
几何攻击是数字图像水印众多攻击的一种,它不试图破坏图像中的水印信号,而是使水印检测器与水印信号失去同步,致使水印检测器检测不到水印信号,是一种有效的水印攻击方法。该文介绍了一种基于标准化的互相关NCC(normalized-cross correlation)图像固有特征提取及特征点匹配方法,进而利用图像固有特征恢复经几何变换的水印图像,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。 相似文献
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旋转攻击是数字图像水印众多攻击的一种,它不试图破坏图像中的水印信号,而是使水印检测器与水印信号失去同步,致使水印检测器检测不到水印信号,是一种有效的水印攻击方法.介绍了一种新颖的数字水印图像检测方法,该检测方法将图像旋转扫描处理与归一化相关值NC(normalized-correlation)计算有机地结合,使水印检测器与水印同步,以达到检测的目的.实验结果表明,使用该检测方法能较好地恢复二值水印图像,对任意角度的旋转攻击都具有较好的鲁棒性. 相似文献
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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。 相似文献
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针对传统的图像检测算法对具有噪声以及光照不足或不均匀的带钢表面图像检测时效果不理想的问题,提出了基于人工免疫系统的带钢表面缺陷检测技术。根据检测器和抗原之间的论域空间包含关系,以及自体在论域空间中的位置信息,引进了分块空间的方式,提出了检测器分块的生成算法,对缺陷图像表面灰度信息进行三维恢复,获得带钢表面缺陷的高度信息,实现其三维质量检测。实验表明,该方法无论是在对比度低、光照不均还是有噪声干扰的情况下相对于传统的图像检测算法具有较好的处理效果。 相似文献
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Canny边缘检测器在计算机视觉中得到广泛应用,它能检测图像形状密度的变化,并寻找图像的边界,在最大密度方向的变化上,如果梯度级象素在边界上大于这些密度象素,Canny边缘检测器能分类这些边缘象素。本文示出了一些未检测的边缘,并作了定义,同时介绍了如何改进Canny边缘检测器以及提高检测的正确率。 相似文献
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针对目前人体检测算法存在不能检测多角度人体目标以及实时性差等问题,提出了一种在静态图像中实时检测任意角度人体目标的算法。该算法分别利用目标颜色和轮廓两类特征构造两种检测器。颜色检测器首先进行基于面部肤色和头部发色的彩色分割,然后引入积分图像算法快速提取分割后的图像头部目标区域。轮廓检测器利用头肩轮廓形状的稳健性,用参数化变形模板对头肩轮廓建模,该模板由两个存在几何尺度和位置约束的椭圆构成,再定义两个不同计算复杂度的模板匹配策略对人体头肩部分进行分级检测。最后利用上述两种检测器构建一个级联检测系统,级联检测结构大大提高了算法的速度,使算法可以对分辨率为352×288的图像做30 fps的实时检测,实验结果表明,该算法是切实有效的。 相似文献
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基于MFA_ICA(Independent Component Analysis based on Mean Field Approximation)理论提出了一种数字图像水印算法。该算法利用MFA_ICA进行水印和原始图像的估计,并用估计出的独立分量检测水印是否存在。与传统线性相关检测器相比,该算法消除了原始载体的干扰,检测性能明显提高。重要的是,不仅通过仿真实验证明了该算法较强抵抗JPEG压缩、剪切和白噪声等攻击的能力,而且从理论上也给出了严格的证明。 相似文献
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Xiang-Yang Wang Pan-Pan Niu Lan Meng Hong-Ying Yang 《Multimedia Tools and Applications》2011,54(2):341-363
Desynchronization attack is known as one of the most difficult attacks to resist, which can desynchronize the location of
the watermark and hence causes incorrect watermark detection. Based on multi-scale SIFT (Scale Invariant Feature Transform)
detector and local image histogram shape invariance, we propose a new content based image watermarking algorithm with good
visual quality and reasonable resistance toward desynchronization attacks in this paper. Firstly, the stable image feature
points are extracted from the original host by using multi-scale SIFT detector, and the local feature regions (LFRs) are constructed
adaptively according to the feature scale theory. Then, the discrete Fourier transform (DFT) is performed on the LFR, and
the local image histogram is extracted from a selected DFT amplitude range. Finally, the bins of the histogram are divided
into many groups, and the digital watermark is embedded into LFR by reassigning the number of DFT amplitudes in bin groups.
By binding the watermark with the geometrically invariant image features, the watermark detection can be done without synchronization
error. Experimental results show that the proposed image watermarking is not only invisible and robust against common image
processing operations such as sharpening, noise adding, and JPEG compression, but also robust against the desynchronization
attacks such as rotation, translation, scaling, row or column removal, and cropping. 相似文献
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Desynchronization attack is known as one of the most difficult attacks to resist, which can desynchronize the location of the watermark and hence causes incorrect watermark detection. It is a challenging work to design a robust image watermarking scheme against desynchronization attacks. Based on multi-scale Harris detector and wavelet moment theory, we propose a new content based image watermarking algorithm with low computational complexity, good visual quality and reasonable resistance toward desynchronization attacks in this paper. Firstly, the steady image feature points are extracted from the origin host by using multi-scale Harris detector, and the local feature regions (LFRs) are constructed adaptively according to the feature scale theory. Then, the LFRs are image normalized, and significant regions are obtained from the normalized LFRs by utilizing the invariant centroid theory. Finally, the digital watermark is embedded into the LFRs by modifying wavelet moment invariants of the significant regions. By binding the watermark with the geometrically invariant image features, the watermark detection can be done without synchronization error. Experimental results show that the proposed image watermarking is not only invisible and robust against common image processing operations as sharpening, noise adding, and JPEG compression etc, but also robust against the desynchronization attacks such as rotation, translation, scaling, row or column removal, cropping, and local random bend etc. 相似文献
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An adaptive image watermarking algorithm based on HMM in wavelet domain is pro- posed.The algorithm is abstracted as follows:1)the vector HMM model is employed to describe the statistical characteristic of image wavelet coefficients and the resulting HMM based detector achieves significant improvements in performance compared to the conventional correlation detector; 2)adaptive watermark embedding based on HVS analysis;3)a novel embedding strategy which is optimized for the HMM tree structure is adopted;4)the strategy of dynamical threshold is applied in watermark detection.High robust results are achieved against Stirmark attacks,such as JPEG compression,adding noise,median cut and filter. 相似文献
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基于小波域HMM模型的自适应图像水印算法 总被引:1,自引:0,他引:1
An adaptive image watermarking algorithm based on HMM in wavelet domain is proposed. The algorithm is abstracted as follows: 1) the vector HMM model is employed to describe the statistical characteristic of image wavelet coefficients and the resulting HMM based detector achieves significant improvements in performance compared to the conventional correlation detector; 2) adaptive watermark embedding based on HVS analysis; 3) a novel embedding strategy which is optimized for the HMM tree structure is adopted; 4) the strategy of dynamical threshold is applied in watermark detection. High robust results are achieved against Stirmark attacks, such as JPEG compression, adding noise, median cut and filter. 相似文献
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DCT变换域乘嵌入图像水印的检测算法 总被引:11,自引:0,他引:11
目前大多数水印算法采用线性相关的方法检测水印,但是,当原始媒体信号不服从高斯分布,或者水印不是以加嵌入方式嵌入到待保护的媒体对象中时,该方法存在一定的问题.数字水印的不可感知性约束决定了水印检测是一个弱信号检测问题,利用这一特性,首先从图像DCT(discrete cosine transform)交流变换系数的统计特性出发,应用广义高斯分布来建立其统计分布模型,然后将水印检测问题转化为二元假设检验问题,以非高斯噪声中弱信号检测的基本理论作为乘嵌入水印的理论检测模型,推导出优化的乘嵌入水印检测算法,并对检测算法进行了实验.结果表明,对于未知嵌入强度的乘水印的盲检测,提出的水印检测器具有良好的检测性能.因此,该检测器能在数字媒体数据的版权保护方面得到了实际的应用. 相似文献