节点文献
基于FPGA的静态图像数字水印处理的实现
【作者】 刘国贺；
【导师】 赖华；
【作者基本信息】 昆明理工大学 ， 测试计量技术及仪器， 2010， 硕士
【摘要】 近年来,随着多媒体处理技术及网络技术的发展,越来越多的数字产品在网络上方便地发布、传播。多媒体处理软件可以对数字媒体(数字音频,文本,图像和视频)的原版进行无限制的编辑、修改。数字产品的的原始性难以得到保证,数字产品的真实性问题受到了广泛关注。数字水印技术(Digital Watermarking)在不影响原始数据正常使用的情况下嵌入防伪信息,并且该信息不易被除去,只能由专用的水印提取算法才能检测其中的信息。数字水印作为保护数字媒体信息安全的有效方法,近年来引起了人们极大的兴趣与注意。因此,数字水印技术作为鉴别数字产品真伪的有效手段,成为多媒体信息安全研究的重点。同时,随着集成电路制造技术的迅速提高,FPGA (Field Programmable Gata Array)芯片的集成度和处理能力都得到了很大的提升,从而使FPGA能够实现复杂电路的功能,并且处理速度也能满足大部份用户的要求。本文提出了一种利用FPGA的电路可编程的特点,设计并实现了数字图像水印处理系统。本文中的数字水印处理系统是在DCT域内进行水印嵌入,先对数字图像进行分块处理,然后选择DCT的高频系数部分作为水印信息的载体。该设计的硬件部分负责二维离散余弦变换(DCT2)与二维离散余弦反变换(IDCT2)的实现,这样就可以将复杂的运算交与硬件电路来实现,大大提高的运算速度；该设计的软件部分负责数字水印信息的嵌入及SD卡的读写,这样即可以缩短研发周期也为系统调试与算法的改进提供了方便。本文简要介绍了数字水印技术和FPGA技术的发展现状及未来方向,研究了典型数字水印算法及其应用领域。通过结合已有的数字水印算法并分析其不足,提出了一种新的算法,此算法与已有的算法相比在数字水印不可见性方面有了很大的提高。在系统硬件架构方面,介绍了片上可编程系统(SOPC)设计方案及开发流程,详细论述了本系统的硬件模块结构并通过数据说明了本结构与传统的软件方式相比在运算速度方面的优势。在系统软件架构方面,介绍了数字水印信息嵌入的流程及各部分的功能。最后通过分析大量的实验数据来进行参数调整,以得到最佳效果。
【Abstract】 In recent years, with the rapid development of the technology of communication and the growing popularity of the Internet, more and more digital information are published and disseminated on the network quickly and easily. Multimedia processing software, and network communication technology make the arbitrary edit, modify, copy and distribute of the original digital media (digital sound, text, images and video) become unrestricting, the piracy problem of digital media has become increasingly serious, the copyright protection issues of digital media has been widespread concerned, the digital watermarking technology has also been duly noted as an advanced way of intellectual property protection.Meanwhile with the continuous improvement of integrated circuit manufacturing technology, the integration and processing speed of FPGA (Field Programmable Gata Array) chips have been greatly improved, which promise FPGA achieving the complex circuit functions, at the same time, the processing speed of FPGA is also able to meet most customer’s requirements.Designing and implementation of a FPGA device, which can be used to realize the watermarking of digital image, on the basis of FPGA-circuit’s feature of programmable in this paper. The device’s hardware components responses for the achieving of two-dimensional discrete cosine transform (DCT2) and the inverse two-dimensional discrete cosine transform (IDCT2); The design of the software components responsible for embedding digital watermark information and the SD card reader, so that can shorten development cycles for system debugging and improved algorithms to provide more convenient.Introducing the digital watermarking technology and FPGA technology development status and future direction to study a typical digital watermarking algorithm and its applications,in this paper. By combining existing digital watermarking algorithm and analyze its shortcomings, presents a new algorithm, this algorithm is compared with existing algorithms in the digital watermark is invisible in terms of greatly improved. In the system hardware architecture, introduced the Programmable System Chip (SOPC) design and development process, discusses in detail the structure of the system’s hardware modules and, through data on the present structure as compared with traditional software’s advantages in computing speed. In the system software architecture, the introduction of digital watermark embedding process and the part of the function. Finally, it analyzes a large number of experimental data to adjust the parameters to get the best results.