发布时间 : 星期四 文章基于MATLAB的数字图像水印技术更新完毕开始阅读
设计题目：基于MATLAB的数字图像水印技术
学 院：计算机科学与信息学院
专 业： 班 级： 学 号： 学生姓名： 指导教师：
2010年 1月 5日
摘要
伴随着多媒体技术和网络技术的的飞速发展，多媒体数据逐渐成为人们获取 信息的重要来源，并成为人们生活的重要组成部分。对数字媒体(数字图像、数 字音频、数字视频)的保护己成为一个迫在眉睫的现实问题。由于传统加密方法 对多媒体内容保护能力有一定的局限性，因此一种新的保护途径应运而生，即数 字水印技术。数字水印是利用数字作品中普遍存在的冗余数据与随机性把版权信 息嵌入数字作品中从而起到保护数字产品版权或完整性的一种技术。
在工程方面选择一种方便高效的工具来实现数字水印算法有重要的意义。MATLAB就是符合这要求的强大的工程计算软件。MATLAB含有十分浩大的函数，本论文主要运用MATLAB语言进行编程实现数字水印技术，探讨数字水印的技术及应用，重点研究一种小型的数字图像水印技术。
本论文主要完成下面工作：
1．从数字水印技术的研究动态、概念、特点、典型算法及其受到的各种形式的攻击作了概括性介绍。
2．由数字图像水印的一般工作流程：嵌入水印、提取水印、攻击、再提取水印，分析和讨论了数字图像水印技术的基本原理和实现过程，最后给出了用MATLAB编写、实现的源代码。
关键词：数字图像，加密，数字水印，MATLAB
I
ABSTRACT
The digital media has become a main way for information communication along with the wide use of network．Have already become an extremely urgent realistic problem to the protection of the digital media(digital picture, digital audio, digital video)．Because the traditional encryption method has certain limitation in protecting ability to the content of the multimedia，so a kind of new protection way arises at the historic moment，named digital watermark technology．Digital watermark utilizes digital works generally exists in the redundant data and randomness of imbed copyright information into digital works to protect the copyright of digital products or integrity of a technology.
Choose a convenient and the high—efficient tool to implement digital watermark algorithm has important significance in engineering．MATLAB is the strong engineering calculation software which accords with this demand．MATLAB contains very huge function. This thesis uses MATLAB program language to realize digital watermark technology, discuss the technology and application of digital watermark and mainly focuses on a small digital image watermark technique.
This thesis finishes the work following mainly：
First，the Paper introduces the digital watermark’s concept，characteristic, typical algorithms and varies of attacks.
Second, the general workflow of digital image watermark is imbed the watermark, draw the watermark, attack, draw the watermark again. The paper analyzes and discusses the basic principle and realization process of the digital image watermark technique and gives implementation of source code written with MATLAB.
Keywords: digital image, encryption, digital watermark, MATLAB
II
目录
摘要................................................................................................................................ I ABSTRACT .................................................................................................................. II 1 引言............................................................................................................................ 1
1．1 选题背景...................................................................................................... 1 1．2 数字水印技术的研究动态.......................................................................... 2 2 数字图像水印技术综述............................................................................................ 3
2．1 数字水印概述.............................................................................................. 3 2．2 数字水印的定义和基本原理...................................................................... 3 2．3 实现数字水印的高效实用工具MATLAB ................................................ 4 3 数字图像水印技术.................................................................................................... 6
3．1 数字水印基本框架...................................................................................... 6 3．2 水印信号的设计和产生.............................................................................. 9 4 数字图像水印技术的MATLAB函数........................................................................ 11
4．1 数据输入输出函数.................................................................................... 11 4．2 产生水印序列的函数................................................................................ 12 4．3 图像显示和图象数据类型........................................................................ 12 4．4 攻击函数.................................................................................................... 13 4．5 本设计所用MATLAB函数 ..................................................................... 13 5 程序运行结果.......................................................................................................... 15
5．1 嵌入水印.................................................................................................... 15 5．2 JPEG压缩及水印提取 ............................................................................. 16 5．3 攻击试验.................................................................................................... 16 5．4 噪声试验.................................................................................................... 17 6 总结.......................................................................................................................... 18 参考文献...................................................................................................................... 19 附录 程序源代码........................................................................................................ 20