基于小波变换的盲水印算法研究

【作者】 罗竞毅；

【导师】 费耀平；

【作者基本信息】 中南大学 ， 通信与信息系统， 2007， 硕士

【摘要】 随着互联网和多媒体技术、通信技术的迅速发展，数字媒体的版权保护问题日益突出，使得数字水印技术备受人们关注。它是目前解决版权保护问题最有效的手段之一。鉴于小波技术发展的日趋成熟以及其在图像处理方面的优越性，本文深入研究了小波域数字图象水印技术。本文分析了数字图象水印技术的原理及典型算法，讨论了数字图象水印的攻击方法和性能评估方法，针对当前的研究现状和存在的问题，重点讨论了如何选取水印的嵌入位置、如何采取嵌入策略和水印的盲提取方法。1．提出了一种结合小波零树结构和奇异值分解的小波域盲水印算法。该算法结合小波零树原理对中低频子带系数进行水印的嵌入的同时，在高频细节子带利用奇异值良好的稳定性能来进行水印的嵌入。因此，该方法在针对高低频的多种攻击下具有良好的鲁棒性的同时，也拥有较大的水印容量。此外，本算法还结合人类视觉系统和图象局部特性来自适应确定量化间隔，使嵌入水印后的图象具有良好的视觉不可见性。2．提出了一种基于整数提升方案小波和小波纹理块的彩色图象鲁棒水印算法。由于整数小波变换实现了整数到整数的映射，不引入量化误差，而考虑到人眼视觉系统亮度掩蔽特性和图像纹理特性，本算法在整数小波变换的基础上使用了分块技术，根据每个小波块的不同亮度和纹理特性对小波块进行选择，并在选出的高亮度和高纹理的小波纹理块中嵌入水印，提高了嵌入水印图像的不可见性。针对彩色图像的原理，对R、G、B分量分别嵌入不同的水印，实现了多种水印的嵌入。实验结果表明，该算法对各重攻击具有较好的稳健性，是一种有效的彩色图象盲水印算法。更多还原

【Abstract】 Along with the development of Internet and Communicationmultimedia techniques, copyright protection of multimedia has becomeincreasingly prominent. More and more people pay attention to thewatermarking technologies. It is the most effective method of copyrightprotection question at present. Whereas the maturity of the wavelettechnology and its advantage in image processing field, a deep researchof digital image watermarking technology based on wavelet domain isdone in this paper.This paper analyzes the digital image watermarking technology andits typical algorithm, discusses the attack and performance evaluationmethods of digital image watermarking. In view of the current researchstatus and problems, this article focuses on how to select the location ofthe watermark, how to adopt embedded strategies and blind extractionmethod of watermark.1. A new blind wavelet domain watermark algorithm based on EZWstructure and SVD is proposed. In the low frequency detal bands, thisalgorithm adopts the EZW structure principle to embed the watermark, Inthe high frequency, uses the Stability of SVD to embed the watermark. So,this alogorithm is more robust under various attack than the traditionalgorithm. Meanwhile, this watermark also has the larger capacity.2. A new blind watermarking algorithm of color images based on in-teger wavelet transform and wavelet texture blocks is proposed. Integerwavelet transform can map integers into integers, which reduces the errormade by floating numbers. Considering of the brightness and image textture masking characteristics of human visual system, this algorithm usessubblock technology on the basis of integer wavelet transform. It choosesthe high brightness and high texture wavelet blocks to implant watermark,so the invisibility of the watermark image is improved. It also achievesmultiple watermark embedding. Experiment results indicate it is aneffective blind color images algorithm.更多还原