【作者】 林涛；

【导师】 杨兆选；

【作者基本信息】 天津大学 ， 信号与信息处理， 2005， 硕士

【摘要】 目前,交通信息的实时监控及分析,对于加强城市交通管理能力起到了越来越重要的作用。为了能够实时地收集交通信息,通过视频检测的方法进行交通检测正在受到越来越多的重视,通过对放置在公路上的摄像机所采集到的路面视频图像的处理,可以获得诸多交通参数,这些参数对于道路交通的自动化管理有着重要的意义。视频交通检测技术已逐渐成为交通信息采集领域的主流技术,具有很好的应用前景。根据市场需求及掌握先进技术的需要,本文研究了视频检测的主要技术,并在此基础上提出了基于DSP的视频交通检测方案。该方案中,对摄像机定标技术进行了深入地研究,并最终确定重建方案,完成了图象坐标系到世界坐标系的转换。同时,使用了基于虚拟检测线的视频检测方法来实时检测车辆,它使用背景差分的原理,将车辆从背景中分割出来。为了提高检测精度,提出了一种新的时空图像序列分析的技术,并将其补充到背景算法中。根据本方案建立的视频交通检测系统采用了C/S结构,客户端完成数据的采集处理,在服务器端完成数据的集中管理功能。在系统硬件方面,使用了基于DSP的视频检测卡加工控机的硬件解决方案,DSP视频检测卡使用了TI公司的C6000系列高性能DSP作为核心处理芯片,可完成模拟信号到数字信号的A/D转换,图象处理等功能。相应地,视频交通检测软件由三部分组成:底层软件、下位机软件、上位机软件。文中介绍了几个重要的软件模块的流程。最后开发出的视频交通检测系统经过对实际路面的试验结果表明,该视频检测系统具有较高的检测精度。更多还原

【Abstract】 Traffic monitoring is of major importance for enforcing traffic management policies. Tocollect traffic information, vehicle detecting based on image analysis techniques has been thoughthighly of more and more. A video camera placed on a point of the road can obtain various trafficparameters, which is the key part of the automatization of traffic management. So video vehicledetection has been a major technology in traffic information collecting area and has a market withgreat potential.According to the demand of market and the need to grasp advanced technology, major videovehicle detecting technologies are researched and a solution based on DSP is presented. In thispaper camera calibration algorithm is detailed and three-dimensional reconstruction solution isadopted which enables to convert image coordinates to world coordinates. At the same time thesolution exploits the algorithm based on virtual loops to detect vehicles in real time, which usesthe background differencing method to segment vehicles from an image. Furthermore a noveltechnology called spatio-temporal image sequences analysis is applied to background differencingto improve detection accuracy. The video vehicle detecting system builded on this solution isconstructed with C/S structure, in which Client is in charge of traffic data collecting andprocessing and Server becomes a management center. Then the hardware implementation on animage board plus computer is described in detail. And the image board with the heart of the TexasInstruments 6211DSP chip has the ability of A/D conversion and video procession. On the aspectof software, the system software is made up of three levels: DSP software, low-level software andhigh-level software. The flow chart of these software components are described in the paper. The final video vehicle detecting system is tested on real-world scenes and experimentresults illuminates that the system can achieve real-time detection of images and a high detectingaccuracy.更多还原