【作者】 孟萃萃；

【导师】 闾国年； 史中超；

【作者基本信息】 南京师范大学 ， 地图学与地理信息系统， 2008， 硕士

【摘要】 数字水印是对数字产品实施版权保护的一种有效技术。然而,目前针对矢量地理数据特性的数字水印检测研究还比较薄弱,远未形成系统的检测理论与有效的检测方法;而且,水印检测只能在侵权发生后对获得的可疑作品进行的诸多限制,更是严重影响了数字水印技术的推广应用。本研究在国家“863”专题课题“GIS矢量数据产品版权保护的关键技术研究”(编号2006AA12Z222)的资助下,针对当前矢量地理数据水印检测研究现状及其特有需求,进行了基于移动Agent的矢量地理数据水印的自主检测方法的研究,以实现对网络上大量可疑侵权矢量地理数据的自主、实时水印检测。论文主要从矢量地理数据水印盲检测、水印自主检测方法和水印检测Agent安全三个方面进行了研究,主要研究内容包括:(1)在对水印检测技术深入分析的基础上,针对矢量地理数据特点及信号特征,研究实现了基于统计方差的空域水印检测、基于量化方式的DWT水印检测、基于乘性方式的DFT水印检测等几种不同的水印检测方法。(2)进行了基于移动Agent的数字水印自主检测模式的研究,构建了原型系统框架,并针对该框架进行了水印检测原型系统的开发和实现。(3)针对水印检测Agent的安全性问题,论文采用加密和数字签名技术,以提高主机和Agent的安全。由于在矢量地理数据中,基于乘性方式嵌入水印需要考虑如何确定统一阈值以及载体数据的统计分布两方面问题,使得归一化相关检测不能作为乘嵌水印的最优检测方法,而基于统计方差的方法则具有较好的鲁棒性和较低的数据形变,较其它算法更适合于应用。另外,结合移动Agent技术实施水印检测的方法可以成为在广域网环境下水印自主检测的一种解决方案,对Agent采用加密和数字签名的方法,可以提高远程Agent主机、Agent及消息的安全性。论文开展的矢量地理数据水印检测方法、基于移动Agent的矢量地理数据水印自主检测模式等研究,具有一定的创新性。更多还原

【Abstract】 Digital watermarking is an effective solution of copyright protection of Vector geographic data. However, the research on digital watermark detection of Vector geographic data is still weak, and the system theory and effective detection method has not yet been established. Furthermore, the watermark was detected or derived to make certain the ownership of the suspected pirate data only after the data was found, and this affected the application of digital watermarking technology seriously. In view of the current status and unique needs of Vector geographic data watermark detection , this dissertation proposes an independent watermark detecting method based on mobile agent to find the pirate data out of the huge amount of vector data distributed over the internet automatically. This study is supported by The HI-TECH Research and Development Program of China (863 Program) ~ Research on Key technique for Copyright Protection of GIS Vector Data (NO.2006AA12Z222).This dissertation includes three main sections to discuss the key problem: blind watermark detection of Vector geographic data, independent watermark detecting method and the security of watermark agent. The major contents of studying of this dissertation are as follows:(1) By analyzing the technique of watermark detection, this dissertation presents 4 watermark detection algorithms of Vector geographic data including spatial algorithm based on statistic variance, algorithm in DWT transform domain based on quantification and algorithm in DFT transform domain based on multiplication in count of the character of the Vector geographic data signal.(2) This dissertation presents an independent watermark detecting method based on Mobile Agent and the framework for watermark detection prototype system has been developed and realized.(3) In order to satisfy the security and privacy requirement of host and watermark agent, this dissertation describes how to apply encryption and digital signature to watermark agent and host.Considering multiple watermark involved uniform threshold and statistical distribution of Vector geographic data, normalization of Correlation-Detection is not suitable for DFT blind watermark detection. Experiments show that the spatial algorithm based on statistic variance is more suitable for application because of robustness and low distoration. Furthermore, the watermark detecting method based on mobile agent this dissertation presented is a viable solution for independent watermark detecting, and encryption and digital signature can improve the security of watermark agent.The innovations of this dissertation mainly include the method of watermark detection of Vector geographic data and the method of initiative watermark detection.更多还原