基天DWT域数字图像水印技术.doc

基于DWT域的数字图像水印技术 摘 要：随着计算网络和多媒体技术的快速发展，特别是Internet的普及，信息安全问题日益突出。如今信息隐藏技术，特别是数字水印技术作为版权保护的重要手段，己经得到广泛的研究和应用。数字图像水印技术作为一种新兴的版权保护技术，其实质是运用图像处理技术实现信息的隐藏。其核心是将数字水印信息嵌入到图像中，同时保证人眼感觉不到图像质量的下降，也即是保证所加入水印的不可见性。这是一种解决版权问题的有效方法。 数字水印技术从根本上说，属于信息隐藏技术，论文首先介绍了数字水印技术的提出背景及意义、研究状况、应用领域、基本特性、分类、基本模型和典型算法等。重点分析了基于离散小波变换的数字图像水印技术的概念及小波变换的原理和算法，以及小波变换在数字水印领域中的应用。设计了一个完整的水印系统，给出了一种基于haar小波变换的数字水印算法，并在Matlab7.0环境下实现了该算法。实验结果表明，该算法在满足视觉不可见性的同时，对常见的图像处理和噪声干扰表现出较强的鲁棒性，提取出的二值图像水印很容易视觉辨认，具备一定的实用价值。 关键词：数字水印；版权保护；离散小波变换；水印嵌入及提取  毕业设计（论文）外文摘要 Digital Image Watermarking Based on DWT Abstract: With the rapid development of network and multimedia techniques, especially the popularization of Internet, the information security problem has become increasingly prominent. Nowadays, the information hiding technology, especially the digital watermarking technology has been extensively researched and applied as an important means to copyright protection. Digital image watermarking technology is a new copyright protection technology whose essence is to use image processing technology to hide information And its core is to embed the digital watermark information into images. At the same time, this technology makes sure that eyes can’t notice the decline of image quality which is to ensure the non-visibility of the adding watermark. This is an effective method to resolve the copyright problem. Fundamentally speaking, the digital watermarking technology belongs to the information hiding technology. The paper firstly discusses the background, basic model and the typical algorithm of the digital watermarking technology .etc. Then the paper focuses on the concept of DWT-based digital image watermarking technology and the principle and algorithms of wavelet transform, as well as the applications of wavelet transform in the field of digital watermarking. Finally, this paper designs a complete watermarking system and presents a digital watermarking algorithm based on haar wavelet which is implemented by MATLAB7