【作者】 宋立；

【导师】 裘正定；

【作者基本信息】 北京交通大学 ， 信号与信息处理， 2008， 硕士

【摘要】 印章域数字水印防伪系统是基于PKI/CA平台,结合印章域数字水印技术搭建的。它可实现电子文档和物理文档的双重防伪作用,将数字水印技术和PKI的应用领域从数字域拓展到了模拟域。因此,印章域数字水印防伪系统的研究很有实用意义。同时,该系统的便携化将让它更有市场实用价值。针对该印章域数字水印防伪系统,本文重点研究了系统中存在的问题,并提出解决思路,设计了解决算法,完善了系统功能。同时,为了系统市场应用的推广,提出了一个水印检测部分便携式开发的实用化方案。论文的主要贡献包括:1.分析了现有印章域数字水印防伪系统中存在的问题,即不能灵活针对多种印章图像进行水印嵌入和提取。提出了解决的思路,即在水印嵌入和提取之前先进行印章图像的分类和识别。设计了基于矩形度、圆形度和不变矩特征的印章图像自动分类和识别算法。最后进行了实验验证,并对实验结果进行了分析总结。2.为数字水印检测部分的便携式开发提供了一个实用化方案。设计并实现了基于NiosⅡ的嵌入式印章水印检测系统。同时使用了C2H硬件加速器对软件算法部分进行了优化,并用实验结果证明了经过加速后,整个执行速度得到了很大的提升,满足了系统期望的实时性要求。更多还原

【Abstract】 Seal domain watermark security system combines PKI/CA platform with the seal domain watermark technology. The system expands the application fields of digital watermark and PKI technology from the digital domain to the analog domain to protect both digital documents and paper documents. Therefore, it has become a research hotspot for its practical utility. What’s more, it would be widely used, if we could make the system completely portable.In this paper, we summarize the main weakness of the existing Seal domain watermark security system. We also find a perfect solution to solve the problem for the system. In the meantime, in order to popularize the Seal domain watermark security system, we raise a design scheme for Portable equipment, and implement the Portable Watermark Detector on FPGA. The valuable research fruits are as follows:1. After analyzing the existing Seal domain watermark security system, we find that it doesn’t support various kinds of seals. According to the problems we have encountered, this paper presents the corresponding solution. Based on the knowledge of rectangular degree, circular degree and moment invariants, we design an algorithm of image classification for seal image. After a lot of experiments, the result proves that this algorithm can help us to solve the problem we have mentioned before.2. Based on our scheme, we implement the Portable Watermark Detector on FPGA. Meanwhile we used the C2H hardware accelerator in order to improve the performance of system. The result proves that the whole speed performance promotes a lot, and meets the real-time requirement.更多还原