基于像素差分的图像隐写算法研究摘要隐写术是一种隐藏通信手段，其目的是避开第三方的怀疑将信息传递出去，在军事、情报、国家安全等方面具有重要的意义。
隐写的基本要求是要有极高的安全性和足够的信息嵌入量。
隐写技术和隐写分析在国家军事、情报、商业等方面的意义重大。
设计高度安全的隐写方法是一项十分紧迫的任务，而对隐写分析的研究同样很重要。
一方面是要以尽可能隐蔽的方式将信息隐藏在载体信号之中，从而不引起对方的怀疑以实现隐蔽通信的目的；另一方面则是要以各种各样的手段检测隐蔽信息的存在，寻找敌对隐蔽通信的信源，从而阻断隐蔽通信的信道。
如同密码分析和密码术之间的对立关系，隐写分析和隐写术之间如同展开了一场“军备竞赛"，伴随着彼此的发展而演化前进。
由于当前针对隐写的主要对抗措施是利用统计分析手段发现数字媒体的统计异常性，因此统计隐蔽性是安全隐写的主要考虑因素。
基于 LSB 的图像隐写方法简单，嵌入量较大；而基于人眼视觉特性的图像隐写算法具有很好的视觉隐蔽性和较大的嵌入量，因此两者都得到了广泛的应用，现在针对它们已经出现了多种有效的隐写分析方法。
本论文对隐写和隐写分析的目的、基本原理、主要方法进行了讨论，对国内外研究现状进行了综述。
系统地分析了现有的隐写算法，针对隐写算法中存在的统计异常，提出抗统计分析、安全性更好的算法，本文提出了一种结合了LSB与边缘匹配的基于像素差分的图像隐写算法，这些是上述算法中所没有提到的，预期希望可以实现兼顾嵌入秘密信息的容量和提高隐写图像的安全性的效果。
关键字：隐写分析；像素值差分；边缘匹配；最优像素调整AbstractSteganographic methods is a kind of hidden communication, its purpose is to avoid the third party doubt information transfer out, in the military, intelligence, such as national security has an important significance. The basic requirement of implicit writing is to have a high safety and enough information embedded quantity. Steganographic techniques and steganalysis in the national military, intelligence, business etc is of great significance. The design of the high security steganographic method is a very urgent task, but to steganalysis also is very important. On the one hand is to as much as possible in a hidden way will information hiding in the carrier signal, thus not cause each other's doubt to achieve the purpose of stealth communication; On the other hand is to all kinds of means testing the existence of hidden information, look for the enemy hidden communication source, thus blocking the concealed communication channel. As code analysis and cryptography confrontation relations, steganalysis and steganographic methods as launched a "arms race", with each other's development and evolution forward.Due to the current steganographic main countermeasures is the use of statistical analysis methods found that digital media statistical abnormality, so statistical disguised is safe hidden write main consideration factors. Based on LSB image steganographic method is simple, embedded in large quantities, And based on human visual characteristics of the image steganographic algorithm has very good visual concealment and larger embedding quantity, so both a wide range of applications, for now they have appeared a variety of effective steganalysis method. This thesis about hidden writing and steganalysis purpose, basic principle, main methods are discussed, the research at home and abroad are reviewed. This paper analyses systematically the existing steganographic algorithm, in view of the steganographic algorithm existing statistical anomaly, and puts forward the resistance to statistical analysis, safety better algorithm,this paper proposes a combined with LSB and edge matching based on pixel difference image steganographic algorithm, these are the above algorithms have not mentioned, the hope can achieve expected to embed secret information capacity and improve the security of the steganographic image effect.Keywords: Steganalysis; Pixel value difference; Edge matching; The optimal adjustment of pixels目录第一章绪论 (1)1.1 研究背景 (1)1.2 课题意义 (1)1.3 研究内容 (2)1.4 论文的组织结构 (3)第二章图像隐写及隐写分析综述 (5)2.1 隐写术的发展 (5)2.2 隐写系统的模型与特征 (6)2.2.1 隐写系统的模型 (6)2.2.2 隐写系统的特征 (6)2.3 数字水印与隐写术 (7)2.4 图像隐写的研究现状 (8)2.5 本章小结 (9)第三章基于像素特征的图像隐写算法研究 (10)3.1 引言 (10)3.2 现有算法的缺陷 (10)3.3 像素特征改进算法 (11)3.3.1 MD5伪随机数算法 (11)3.3.2 图像置乱预处理 (12)3.3.3基于边缘的整数小波域自适应隐写算法 (12)3.3.4阈值 T 的计算 (13)3.3.5数据的嵌入与提取 (14)3.4 实验结果及分析 (15)3.5 本章小结 (17)第四章基于像素值差分的边缘匹配隐写算法研究 (18)4.1 引言 (18)4.2 现有算法的缺陷 (18)4.3 边缘匹配改进算法 (19)4.3.1 MD5伪随机数算法 (19)4.3.2 图像置乱预处理 (19)4.3.3 四边边缘匹配隐写算法 (20)4.3.4 九边边缘匹配隐写算法 (22)4.3.6 信息提取算法 (26)4.4 实验结果与分析 (26)4.5本章小结 (28)第五章总结与展望 (29)5.1 总结 (29)5.2 展望 (30)参考文献 (31)致谢 (34)第一章绪论1.1 研究背景20世纪90年代以来，随着计算机网络的普及和信号处理技术的飞速发展，图像、视频、音频等多媒体数据能够在通信网络中迅速的传输，给人们的生活带来了诸多便捷，改变了传统的通信方式，一些私人秘密、商业机密和军事情报等也通过互联网进行传送。
