嵌入式图像采集和远程传输系统的设计

发布时间：2018-08-13 08:20

【摘要】：在当今信息时代，随着人们对安防意识的逐渐增强，视频监控系统已经广泛应用到各行各业中，作为监控行业的一个重要分支和组成部分-嵌入式网络视频监控系统，发挥着其不可轻视的作用。本设计将新兴的嵌入式技术-可编程的片上系统SOPC(Syetem OnProgrammable Chip)应用于远程图像监控系统中，充分发挥了其硬件电路的高速并行运算能力和软件控制灵活的优点，不仅提高了系统的集成度和稳定性，而且也提高了图像采集和处理速度。首先，本系统中图像采集、存储等计算复杂、高度耗时的功能模块，采用Verilog硬件描述语言来完成。而网卡控制器和图像采集控制器是采用本系统定制的IP核，通过Verilog语言和基于NiosⅡ软核的C语言协调设计完成，从而可实现对图像采集的开关和曝光时间控制。本系统的图像压缩算法采用JPEG标准，并对JPEG编码过程中的离散余弦变换2D-DCT进行了优化。其次，利用Altera公司的NiosⅡ处理器已经移植的MicroC/OS-Ⅱ操作系统作为软件平台，本系统在其内移植了LWIP协议栈，开发了DM9000A网卡驱动程序，并且采用标准socket接口，通过以太网进行网络通信，从而实现了网络实时监控功能。在确定了系统的结构和功能的基础上，对可实现监控功能的多种嵌入式方案进行了对比和分析，从而确定了系统总体设计方案及框架；接着分析了图像采集、图像缓存、JPEG图像压缩算法的优化和图像码流以太网传输的原理和实现方法；并且研究了MicroC/OS-Ⅱ操作系统和LWIP协议栈在NiosⅡ下的移植方法，以及DM9000A网卡的驱动程序编写方法，最后给出了系统软件的总体设计流程。最后，对系统各个主要功能模块进行了仿真测试，并给出了验证结果，实验结果表明，系统实现了图像采集、压缩和以太网传输功能。
[Abstract]:In today's information age, with the increasing awareness of security, video surveillance system has been widely used in all walks of life. As an important branch and component of the surveillance industry, embedded network video surveillance system plays an important role.
In this design, the programmable SOPC (Syetem On Programmable Chip), a new embedded technology, is applied to the remote image monitoring system. The advantages of high-speed parallel computing ability of hardware circuit and flexible software control are brought into full play. It not only improves the integration and stability of the system, but also improves the image acquisition and processing. Processing speed.
Firstly, the system uses Verilog Hardware Description Language to complete the function modules of image acquisition and storage, which are complicated and time-consuming. The network card controller and image acquisition controller are designed by using the IP core customized by this system, and are coordinated by Verilog language and C language based on Nios II soft core, so that image acquisition can be realized. The image compression algorithm of this system adopts JPEG standard, and optimizes the discrete cosine transform (DCT) in the process of JPEG coding.
Secondly, using the MicroC/OS-II operating system which has been transplanted by Altera's Nios II processor as the software platform, the system transplants the LWIP protocol stack, develops the DM9000A network card driver, and uses the standard socket interface to communicate with the network through Ethernet, thus realizing the network real-time monitoring function.
On the basis of determining the structure and function of the system, the paper compares and analyzes various embedded schemes which can realize the monitoring function, and then determines the overall design scheme and framework of the system; then it analyzes the principles and implementation methods of image acquisition, image caching, JPEG image compression algorithm optimization and image bitstream Ethernet transmission. At last, the overall design flow of the system software is given. Finally, the main function modules of the system are simulated and tested, and the verification results are given. The experimental results show that the system is real. Now we have the functions of image acquisition, compression and Ethernet transmission.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP368.1;TP391.41

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