【作者】 陈泗勇；

【导师】 丁兴号；

【作者基本信息】 厦门大学 ， 信号与信息处理， 2009， 硕士

【摘要】 近年来,随着社会物质水平的不断提高,人们对安全防范和现场记录报警系统的需求越来越大,要求也越来越高,从而促进了视频监控系统的普及和快速发展。目前市场的视频监控系统多以图像采集卡采集图像,并借助于微机系统的高速运算能力和大容量存储器来完成对视频图像的实时压缩和存储等。这类系统能够即压即存,但同时带来体积大、成本高、工作稳定性差和感兴趣内容检索麻烦等不足。随着视频监控系统的快速普及,市场划分也越来越细,传统的视频监控系统覆盖所有应用,性价比不高。本文针对场景变化不是很频繁的监控场合(家庭监控、重要仪器设备监控、野生动物调查监控等领域),设计、开发了一款嵌入式多路视频监控记录系统。该视频监控系统能够实时监测三个不同场景,采用H.264在DM642上完成3路视频的实时软压缩,由于是软压缩,可以针对不同应用调节视频图像质量和码流,方便系统的升级;采用CF卡代替大容量的硬盘存储,减小了系统的体积、增强稳定性的同时降低了系统的成本;抛弃传统视频监控系统即压即存的方式,改用运动检测算法来监测场景变化,记录变化前后一段时间的视频,减小对存储容量要求的同时方便对感兴趣视频的检索。本文致力于整个系统的实现,主要研究内容如下:1.介绍运动检测算法的基本原理,分析一些常用运动检测算法,以此为基础提出适合本系统的运动检测算法。2.简要介绍视频压缩标准发展历程,介绍各种压缩标准的优缺点。重点讲解H.264标准的主要特征及其编解码器的基本原理。3.以DM642为核心,由最小系统的设计到外围接口的扩展,详细讲述系统的硬件平台原理图设计、PCB设计及系统硬件平台的调试。4.深入研究DSP/BIOS操作系统内核的工作原理和线程调度机制及ReferenceFramework5框架的结构,以此为基础开发整个系统应用软件。更多还原

【Abstract】 Recently,with the constant improvement of social material living standards,the demand for security and on-site alarm system grows rapidly and the requirements are getting higher,it improves the popularity and rapid development of video monitoring system.Nowadays,video monitoring system on the market often uses image acquisition card to acquire image,and it relies on computer system’s high-speed computational capability and bulk memory to perform real-time compression and storage of video image.Such system can save video immediately after compression, but it also has the disadvantages,such as bulky in volume,expensive in cost,unstable in work and troublesome in interested content retrieval.With the rapid spread of the video monitoring system,the functions of monitoring system are more detailed.Although traditional video monitoring system covers all applications,the cost performance is not so good.This paper is dedicated to the design and development of a multi-channel embedded video monitoring system aiming for backgrounds with rare change in scenes,such as home,important equipment and wildlife survey monitoring.This system can perform real-time monitoring on three different scenes at the same time by using H.264 software to compress three channel video at real-time on DM642 chip.It can adjust the video image quality and stream for different applications and facilitate system upgrade since soft compression is applied.Using CF card instead of large capacity hard disk storage reduces the bulk of the system,enhances the system stability and decreases the system cost.The tradition way of saving video immediately after compression is abandoned, instead,motion detection algorithm is adopted to monitor the change in scenes,that is, just recording the video image before and after scene change over a period of time if the scene is changed,which can reduce requirements for storage capacity and also facilitate the retrieval of interested video.This paper is committed to the realization of the whole system,the main research contents are as follows:1.Introducing the basic principles of motion detection algorithm,analyzing some common motion detection algorithm,and putting forward a new motion detection algorithm for this system on this basis.2.Briefly introducing the development of video compression standards and their advantages and disadvantages,then focusing on the main characteristics of H.264 standard and the basic principles of its codec.3.Elaborating the design of schematic diagram of hardware platform of the system,PCB deign and hardware debug from the smallest system design to the expansion of periphery interface with DM642 as the central processor.4.In-depth study of the working principles of DSP/BIOS operating system kernel,thread scheduling mechanism and structure of Reference framework 5,and developing the application software of the system based on the study.更多还原