共查询到20条相似文献,搜索用时 203 毫秒
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本文基于文本数字水印的特征编码思想,通过设置Word文档中字符的下划线格式以嵌入和检测水印。实验表明,该算法有较强的不可见性,能较好的嵌入和检测水印,从而达到数字水印的一般要求。 相似文献
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数字水印技术是通过特定的算法将一些标志性信息嵌入到多媒体内容当中,但不影响原内容的价值和使用,并且不能被人的知觉系统觉察或注意到,只有通过专用的检测器或阅读器才能提取的技术。文本数字水印是以文本为载体的数字水印,它是数字水印研究领域也是信息隐藏处理领域中最具挑战性、最为活跃的研究课题之一。在简单介绍数字水印的基础上概述了文本数字水印技术,并给出了几种常见文本水印的算法及应用。 相似文献
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在分析二值图像文档水印技术研究动态的基础上,通过对汉字特点的分析,发现横、竖笔画频繁交汇出现-拐点。基于此,提出一种新的应用于汉字文本图像的简便水印方法:在汉字笔画横竖交叉的拐点处加入水印,并利用MatLab进行仿真实验,讨论和分析了这一算法较传统的完全基于格式的文本数字水印的优点。 相似文献
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通过对WORD页面描述机制的分析,提出了一种适用于WORD文档保护的数字水印算法。修改文本块中不同字符的字体颜色值,将水印以正弦波的特征形式嵌入文本中。检测时通过提取字体颜色特征,重构正弦波来鉴定文档。实验结果表明,该算法实现的水印具有较好的视觉透明性和检错能力。 相似文献
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本文基于数字水印对于版权保护的作用,从数字水印嵌入原理,嵌入水印信息要求出发,综合DWT(离散小波变换)对图像分解的特点,以及数字水印的鲁棒性与不可见性要求,提出一种基于DWT和HVS(人类视觉系统)的图像数字水印技术。这种数字水印方法在保证数字水印不可见性的同时,确保数字水印在对加水印图像进行JPEG压缩、加噪、中值滤波等处理具有较强的鲁棒性。 相似文献
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数字水印技术在数字产品的版权保护中起着非常重要的作用,文章简要介绍了数字水印的背景知识、研究现状、常见的水印攻击方法,最后展望了数字水印的研究和发展方向。 相似文献
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数字水印是永久镶嵌在其他数据(宿主数据或载体数据)中具有可鉴别性的数字信号或模式。图像水印是以静止数字图像为载体的数字水印,它是数字水印研究领域也是数字图像处理领域中最具挑战性、最为活跃的研究课题之一。本文在简单介绍数字水印的基础上概述了图像水印技术,并给出了一些图像水印的算法及应用。 相似文献
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《Information processing & management》2023,60(1):103122
Aiming at the problem that watermark information is easy to be lost in two-dimensional text image watermarking, a three-dimensional text image watermarking model is proposed based on multilayer overlapping of extracted two-dimensional information, and a specific method is accordingly realized by means of embedding, extracting and overlapping of multiple watermarks in sequence. We discuss the influence of the sequence order, positional distancing and color difference of the extracted multiple two-dimensional information on displaying a three-dimensional text watermark image. In addition, considering the crucial evaluation indices of the invisibility and robustness for the watermarking algorithm, the selection method for superior embedding regions of multiple watermarks is also constructed to enhance the robust performance of watermarks under the premise of effective invisibility. Moreover, we embed the multiple two-dimensional information into the host image by using the undecimated dual-tree complex wavelet transforms - bidiagonal singular value decomposition algorithm. In this way, the extracted multiple two-dimensional information is automatically overlapped to generate the three-dimensional text watermarking according to the optimal matching parameters. We use standard image processing data set to carry out experiments, the results show that the peak signal to noise ratio before and after embedded watermarks is higher than 39 dB, and the peak signal to noise ratio between the original watermarks and the extracted watermarks is more than 37 dB, which is superior to the current reported watermark model. Therefore, it is suggested that the proposed model shows good invisibility and robustness and can reduce the loss of watermark during transmission and attack as much as possible. 相似文献
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随着计算机技术及通信网络技术的迅速发展,数字信息资源的数量越来越多,对其版权保护问题日益突出。文章分析了数字文本文档和数字图像的应用现状及其存储形式,并详细介绍了在不同数字信息资源下利用数字水印技术进行版权保护的思路和方法。指出数字水印在数字版权保护中存在的问题及研究方向。 相似文献
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通过Shannon熵算法采用自下向上的搜索方法选取最优小波包基,分别对原始图像和水印图像进行小波包分解,把水印数据嵌入选定的原始图像小波包基中。经攻击实验表明,应用本算法所实现的水印不可见,较好地保持了图像的质量,同时显示了较强的鲁棒性。 相似文献
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本文提出了一种将彩色数字水印嵌入到彩色载体图像的新算法,利用改进的Patchwork方法将一级小波分解的水印图像的低频部分分别四次嵌入到经过离散余弦变换和离散小波变换后的载体图像的RGB分量中,提取的时候,将四次嵌入的低频分量取出并求平均值,用来作为水印的最终低频分量。经过实验验证,该算法对很多攻击具有很好的鲁棒性。 相似文献
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Hanaa A. Abdallah Rania A. Ghazy Hany Kasban Osama S. Faragallah Abdalhameed A. Shaalan Mohiy M. Hadhoud Moawad I. Dessouky Nawal A. El-Fishawy Saleh A. Alshebeili Fathi E. Abd El-samie 《Information processing & management》2014
In this paper, a new homomorphic image watermarking method implementing the Singular Value Decomposition (SVD) algorithm is presented. The idea of the proposed method is based on embedding the watermark with the SVD algorithm in the reflectance component after applying the homomorphic transform. The reflectance component contains most of the image features but with low energy, and hence watermarks embedded in this component will be invisible. A block-by-block implementation of the proposed method is also introduced. The watermark embedding on a block-by-block basis makes the watermark more robust to attacks. A comparison study between the proposed method and the traditional SVD watermarking method is presented in the presence of attacks. The proposed method is more robust to various attacks. The embedding of chaotic encrypted watermarks is also investigated in this paper to increase the level of security. 相似文献
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《Journal of The Franklin Institute》2023,360(7):4493-4518
This paper presents a new robust multiplicative watermark detector. Due to the strong robustness against various attacks, polar harmonic Fourier moment (PHFM) magnitudes are used as the employed watermark carrier. The distribution of PHFM magnitudes is highly non-Gaussian and can be properly modeled by a heavy-tailed probability density function (PDF). In this paper, we proved that Weibull distribution can suitably fit the distribution of PHFM magnitudes, and based on this, we presented a statistics-based watermark decoder by using the Weibull as a prior for the PHFM magnitudes. In watermark embedding, a multiplicative manner was used to embed watermark information in PHFM magnitudes of the highest entropy blocks to achieve better robustness and imperceptibility. In watermark detection, we developed a Weibull distribution-based statistical watermark decoder, which uses the maximum likelihood (ML) decision rule. Compared with Bessel K form (BKF), Cauchy, and generalized Gaussian (GG)-based decoders, the Weibull-based decoder demonstrates stronger robustness. In addition, the proposed watermark decoder is more robust against geometrical and common image processing attacks than existing statistical watermark decoders. 相似文献