基于小波变换的数字水印嵌入式算法研究中英摘要

基于小波变换的数字水印嵌入式算法研究
摘要：随着信息技术特别是网络技术的发展，电子媒体传播极为迅捷，对数字多媒体信息的获取也越来越容易，但同时，数字媒体产品信息的版权、保密等问题也变得日益突出起来，所以多媒体的信息安全保护成了一个研究热点。

数字图像水印技术作为一种新兴的版权保护技术，是对数字媒体产品进行版权保护的有效方法之一。

它实际上是利用数字图像处理技术来实现信息隐藏。

用于版权保护的数字水印设计的关键是水印信息嵌入的隐蔽性和抵抗攻击的鲁棒性。

本文首先对密码技术、信息隐藏技术进行了综述，然后具体介绍了数字水印的相关概念、应用领域、发展状况、基本特征及典型算法，并描述了小波变换的概念及小波变换的原理和方法；最后讲描述了小波变换在数字水印领域中的应用，最后实现了并详细描述了一种基于DWT域扩频水印算法。

通过一级离散小波变换将图象分成4个子块，在嵌入水印时，使用伪随机序列来实现扩频，然后再嵌入到其中两个中频子图中，最后进行离散小波逆变换，得到含水印图象。

仿真结果表明，含水印图像的视觉质量较好。

在没有遭受攻击时，可以100%提取水印，具有较强的鲁棒性。

关键词：数字水印，信息隐藏，离散小波变换，扩频
The digital water marking embedded algorithm research based
on the wavelet transform
Abstract：With the rapid development of information technology, especially the growing of Internet, the spread of digital media is very swift, and the getting of digital information is more convenient and quicker. At the same time, the question of digital media copyright protection and authentication is becoming more and more important, thus digital multimedia copyright and security have become one of hotspot questions. Digital image watermarking is a kind of new technology for copyright protection, and is also one of effective methods to protect digital multimedia. In fact this technique utilizes image process methods to hide some information. The key of digital watermark to copyright protection is the imperceptibility and robustness for embedded information.
This article first cryptographic techniques, hidden information technology were reviewed, and then introduced a number of specific watermark of related concepts, applications, development of the basic characteristics and the typical algorithm, and on the wavelet transform the concept of wavelet transform and the principles and methods; Finally on the wavelet transform the digital watermark in the field of application and a detailed description of a spread spectrum-based DWT domain watermarking algorithm. Images will be divided into four sub-block through the one discrete wavelet transform，When the embedded watermark, using the pseudo-random sequence spread spectrum to achieve, and then embedded into two sub-plans in IF, finally, inversing discrete wavelet transform, being with watermark images. The simulation results show that the quality of the visual of the watermarked image is better. When the absence of the attack, it can be extracted watermark 100 per cent, and it is robust
Key Words:Digital watermarking, Information hiding, Discrete Wavelet transform, Spreading。