【作者】 杨洁；

【导师】 张敏瑞；

【作者基本信息】 西安科技大学 ， 通信与信息系统， 2006， 硕士

【摘要】 数字文本水印技术可以有效解决数字文本媒体的版权保护问题。近年来，数字文本水印技术的研究比较分散，缺乏系统理论，没有突破性的研究进展。 本文主要依据数字文本的特点，研究了数字文本图像的水印嵌入和提取算法。首先介绍了数字文本水印的基本概念、研究现状和应用情况，分析了现有文本水印算法和其特点，给出了分类及文本水印的算法评价。最后重点研究了空域和变换域数字文本水印算法。在空域算法中，利用二值文本图像的结构特征，研究了基于行移、字移编码的二值文本水印算法，实现了二值文本图像水印的嵌入与提取。实验结果表明，该算法可以有效地实现水印的嵌入和提取，并且具有较强的鲁棒性。在变换域算法中，分别研究了基于DCT域、DWT域、整块DCT-DWT域和分块DCT-DWT域的数字文本图像水印算法，并用MATLAB语言分别实现了文本图像水印的嵌入和提取。实验结果表明，这些变换域算法可以有效地实现水印的嵌入和提取。更多还原

【Abstract】 Digital document watermarking technology can be used to solve effectively the copyright protection problem of digital document media. Recent years, the study is dispersive relatively, and is short of system theory, moreover is out of breakthrough.This thesis mainly studies watermarking embedding and extracting algorithms for digital document images according to their characteristics. First the basic conception, the current research states and the application conditions of digital document watermarking are introduced, then the existing algorithms and their features are analyzed, the classification and the evaluation for digital document images are given, finally the emphases are focused on the space and the transform domain watermarking algorithms for digital documents. In space domain, line shift and word shift coding are used to embedding a watermark in a digital document according to their structure characteristics, the embedding and extracting algorithms are implemented. The experimental results show that this algorithm is effectively and has strong robustness. In transform domain, the discrete cosine transform (DCT), discrete wavelet transform (DWT) , DCT-DWT and blocked DCT-DWT algorithms are studied, the embedding and extracting process are realized in MATLAB language. The experimental results show that these algorithms can embed and extract watermark information effectively.更多还原