摘要:随着时代的发展,数字水印在视频、音像的版权保护方面越来越有着巨大的应用潜力。目前,有大量的数字水印算法被提出,小波变换是其中之一。其中之一原因是图像高频域水印算法可以利用人眼的视觉特性(Human Visual System,HVS)提高水印的性能。在遇到各种常见攻击时,离散小波变换算法(Discrete Wavelet Transform,DWT)又出现了一些不足,所以学者将离散小波变换和奇异值分解(Singular Value Decomposition,SVD)相结合,既保存了DWT本身的优势,又利用SVD使算法的鲁棒性提高。35213
首先本文综合性介绍了数字水印的原理、研究现状以及各方面的应用,接着以公式为辅助具体讲述了DWT和DWT-SVD两种算法中水印嵌入、提取以及检测的过程,最后从实际上采用MATLAB平台,模拟各种几何攻击,用图片和表格形式展现出两种算法的优劣。 毕业论文关键词:小波变换 数字水印 DWT-SVD DWT 鲁棒性
Technology Research of Digital Watermarking Based on Wavelet Transform
Abstract:With the development of the era, digital watermarking plays more and more important roles in the copyright protection of audio and video.At present, large number of digital watermarking algorithms have been proposed,and wavelet transform is one of the important algorithms. One of the reasons is that watermarking algorithm of high-frequent-domain image can take advantage of Human Visual System (HVS) to improve the performance of the watermark. However, when meeting a variety of common attack, Discrete Wavelet Transform(DWT) algorithm has some shortage.Therefore, researchers combine Discrete Wavelet Transform and Singular Value Decomposition (SVD) .The new algorithm not only preserves DWT itself advantages,but also can use SVD to improve the robustness of the algorithm.
Firstly,this paper makes a comprehensive introduction about digital watermarking,including principles,the current development status and the application of various aspects.Secondly, assisted by formula,the article introduces DWT and DWT-SVD algorithms of watermark embedding, extraction and detection proces.Lastly, in practice with the MATLAB platform, we make two algorithms suffer all kinds of geometric attacks, in the form of pictures and tables to show the advantages and disadvantages of two algorithms.
Keywords:wavelet transform the digital watermark DWT-SVD DWT robustness
目录
1 绪论 1
1.1研究背景 1
1.2研究现状 1
1.3研究的理论意义 2
1. 4数字水印算法的分类 2
1.5本文的主要内容 3
2 数字水印技术的原理 4
2.1数字水印的概念 4
2.2数字水印的特点 4
2.3数字水印技术的基本原理 4
2.4数字水印技术的划分 6
2.5数字水印技术的应用 6
3 基于离散小波变换的数字水印算法 8
3.1小波变换的发展历史 8
3.2小波变换的定义 8
3.3离散小波变换 10
3.4基于小波变换的数字水印的基本流程 10
4基于DWT-SVD算法的数字水印算法分析 14
4.1奇异值分解 14
4.2水印的嵌入 15