基于数字水印的图像认证技术研究
发布时间：2018-07-18 14:20
【摘要】：数字水印是一种有效的数字产品版权保护和数据安全维护技术,是信息隐藏技术研究领域的一个重要分支。采用数字水印技术进行图像认证,具有与数字签名不同的优势,它已经成为当前信息认证领域研究的热点。本文比较系统地研究了数字水印的重要分支一认证水印(脆弱性数字水印和半脆弱性数字水印)的发展情况:论述了认证水印提出的背景、基本框架;重点分析了脆弱性数字水印和半脆弱性数字水印现有的各种算法,比较了它们的优缺点,在此基础上提出了三种认证方案。 在方案一中,本文提出了一种新的摘要提取方法,通过理论分析及上万次的仿真,证明:该方法可以获得较短的摘要长度,并且当输入发生变化时,该方法产生的摘要比采用Hash函数奇偶校验位和Hash-hamming重量的方法具有更高的变化概率。在此基础上,提出了一种新的脆弱性数字水印算法,理论及实验结果证明该方法具有很高的图像篡改检测概率;较高的篡改定位精度;同时可以较好的保持图像的使用价值;算法简单、安全性高,具有较好的实用性。 在方案二中,本文将方案一的方法进一步扩展到半脆弱性数字水印中。首先提出了一种新的图像预处理方法,该方法可以使图像具有很好的抗JPEG压缩能力。其次,本文在应用预量化原理的基础上,将提取出的水印信息嵌入到DCT交流系数中,使得图像在压缩后水印信息可以完全重构。该方案不仅可以区分正常的压缩和篡改,而且可以进行篡改准确定位,同时具有很高的篡改检测概率。方案的实现算法简单,安全性高。仿真实验结果证明了方案的有效性。另外,在方案中本文还提出了一种新的篡改定位方法—区域定位和交叉定位复合的方法,这种方法可以有效减少误判。 在以上研究的基础上,本文对DWT域的半脆弱水印也进行了相关研究。
[Abstract]:Digital watermarking is an effective digital product copyright protection and data security maintenance technology, is an important branch of information hiding technology. Image authentication based on digital watermarking has different advantages from digital signature, and it has become a hot topic in the field of information authentication. In this paper, the development of authentication watermarking (fragile digital watermarking and semi-fragile digital watermarking), an important branch of digital watermarking, is systematically studied. The background and basic framework of authentication watermarking are discussed. The existing algorithms of fragile digital watermarking and semi-fragile digital watermarking are analyzed, their advantages and disadvantages are compared, and three authentication schemes are proposed. In the first scheme, a new abstract extraction method is proposed. Through theoretical analysis and thousands of simulations, it is proved that the method can obtain a shorter length of abstract, and when the input changes, The method has a higher probability of variation than that of using Hash function parity check bits and Hash-hamming weights. On this basis, a new fragile digital watermarking algorithm is proposed. The theoretical and experimental results show that this method has high image tamper detection probability, high tamper location accuracy, and can maintain the value of image. The algorithm is simple, safe and practical. In the second scheme, the method of scheme one is further extended to semi-fragile digital watermarking. Firstly, a new image preprocessing method is proposed, which can make the image have a good ability to resist JPEG compression. Secondly, based on the principle of prequantization, the extracted watermark information is embedded into the AC coefficients of DCT, so that the watermark information can be reconstructed completely after compression. This scheme can not only distinguish the normal compression from the tamper, but also can locate the tamper accurately, and has a high probability of tampering detection. The algorithm of the scheme is simple and the security is high. The simulation results show that the scheme is effective. In addition, a new tamper localization method, the combination of region location and cross location, is proposed in this paper, which can effectively reduce misjudgment. Based on the above research, this paper also studies the semi-fragile watermark in DWT domain.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：TP309.7
本文编号：2132170
[Abstract]:Digital watermarking is an effective digital product copyright protection and data security maintenance technology, is an important branch of information hiding technology. Image authentication based on digital watermarking has different advantages from digital signature, and it has become a hot topic in the field of information authentication. In this paper, the development of authentication watermarking (fragile digital watermarking and semi-fragile digital watermarking), an important branch of digital watermarking, is systematically studied. The background and basic framework of authentication watermarking are discussed. The existing algorithms of fragile digital watermarking and semi-fragile digital watermarking are analyzed, their advantages and disadvantages are compared, and three authentication schemes are proposed. In the first scheme, a new abstract extraction method is proposed. Through theoretical analysis and thousands of simulations, it is proved that the method can obtain a shorter length of abstract, and when the input changes, The method has a higher probability of variation than that of using Hash function parity check bits and Hash-hamming weights. On this basis, a new fragile digital watermarking algorithm is proposed. The theoretical and experimental results show that this method has high image tamper detection probability, high tamper location accuracy, and can maintain the value of image. The algorithm is simple, safe and practical. In the second scheme, the method of scheme one is further extended to semi-fragile digital watermarking. Firstly, a new image preprocessing method is proposed, which can make the image have a good ability to resist JPEG compression. Secondly, based on the principle of prequantization, the extracted watermark information is embedded into the AC coefficients of DCT, so that the watermark information can be reconstructed completely after compression. This scheme can not only distinguish the normal compression from the tamper, but also can locate the tamper accurately, and has a high probability of tampering detection. The algorithm of the scheme is simple and the security is high. The simulation results show that the scheme is effective. In addition, a new tamper localization method, the combination of region location and cross location, is proposed in this paper, which can effectively reduce misjudgment. Based on the above research, this paper also studies the semi-fragile watermark in DWT domain.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：TP309.7
【引证文献】
中国硕士学位论文全文数据库 前1条
1 董萱;基于脆弱水印的图像认证技术研究[D];西安电子科技大学;2011年
，本文编号：2132170
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