基于多摄像头监控的人体跌倒检测算法

人口老龄化使得空巢老人数量越来越多。跌倒作为威胁独居老人生命安全的主要因素受到了社会的广泛关注。为保护老人的生命健康不受威胁,本文提出一种基于计算机视觉的两级人体跌倒检测算法。从监控摄像机中采集视频数据,对其做前景提取,通过形态学操作为前景块绘制矩形边界,根据矩形宽高比从中筛选出所有可能是跌倒的行为,这是粗粒度级检测。之后再用统计学方法对第一级检测出的前景块绘制椭圆边界,分析其形态变化,最终检测出跌倒行为,这是细粒度级检测。本文在开源多摄像头跌倒数据集上进行了评估。仿真实验和与当前的先进方法的对比表明本文算法取得了非常好的效果。     

A photogrammetric application in virtual sport training

The paper discusses an application of close range photogrammetry for the development of a virtual training system for rugby football, and the use of the technique for the evaluation of rugby players' performance. NuView, a stereo-imaging device, and a digital high-definition video (HDV) camera were used to capture stereoscopic video footage of players during field training. The left view and the right view were colour-tinted cyan and red, respectively. The tinted stereo (anaglyph) views were projected onto a white screen, and players were instructed to practise ball-throwing at the screen. A custom-built laser device (TAM) measured the accuracy of the virtual throws. In addition, a photogrammetric system was used to track the movement of body segments, for example, the angle of shoulder orientation and the trunk flexion of the thrower. The measurements determined the parameters needed for an accurate throw and these parameters would be used in the training of new players. The study shows statistically significant differences in the values of these parameters between experienced and inexperienced players.     

Automated mapping of the intertidal beach bathymetry from video images

This paper presents a fully automated procedure to derive the intertidal beach bathymetry on a daily basis from video images of low-sloping beaches that are characterised by the intermittent emergence of intertidal bars. Bathymetry data are obtained by automated and repeated mapping of shorelines from video time exposure images for different (tidal) water levels (Aarninkhof, S.G.J., Turner, I.L., Dronkers, T.D.T., Caljouw, M., Nipius, L., 2003. A video-based technique for mapping intertidal beach bathymetry. Coastal Engineering 49, 275–289; Plant, N.G. and Holman, R.A., 1997. Intertidal beach profile estimation using video images. Marine Geology 140, 1–24.). The developed procedure handles intelligent selection of a shoreline search area and unsupervised quality control of the obtained bathymetry data. The automatically retrieved beach bathymetries compare very well to bathymetries derived from the original manual mapping procedure and to ground truth data points (DGPS).     

基于LINUX及QT/Embedded的点对点视频会议系统的实现

介绍了目前广泛应用于嵌入式系统的QT类库实现视频会议系统的功能,主要包括了视频音频采集编码模块、网络控制传输模块、视频音频显示播放模块。最终在ARM-S3C2410平台上实现。     

基于视频的交通流参数智能检测系统研究

实现了一种利用计算机视觉和图像处理的方法来检测车流的智能检测系统。首先利用输入的图像序列完成自适应的背景重建,通过目标分割和特征提取实现目标检测和运动跟踪,然后提出将HSV颜色空间特征应用于车辆目标匹配的方法和一种新的快速非均匀量化算法,用于跟踪发生融合的目标,最后对各交通流参数进行计算和统计,并对系统实现过程中出现的问题进行分析和总结。     

MS-FORTRAN图形接口及其应用程序设计方法

本文着重讨论了 Ｍ ｉｃｒｏｓｏｆｔ Ｆ Ｏ Ｒ Ｔ Ｒ Ａ Ｎ ５．１ 系统（下面简称 Ｍ Ｓ Ｆ５．１ 系统）的图形接口、数据结构以及输出图元的过程,并用实例说明了图形应用程序的设计方法。     

基于社会视频监控信息源的地震影响范围快速勾画

广泛分布于城乡各地的社会视频监控是震后获取地震灾情的重要数据源。基于地震视频灾情判读系统,对基于视频运动估计方法的主要技术原理和分析处理过程进行改进,并将其应用于2017年浙江临安4.2级地震影响场快速评估中。结果表明:利用该改进方法在震后4h内得到了基于社会监控的烈度分布,计算得到的最高烈度与现场实际调查相同,等震线优势方向与现场工作结果一致,V度面积和现场工作结果接近。     

MPEG4在海底彩色电视监控系统中的应用

研发深海电视监控系统使海洋调查人员能够对海底微地形、地貌和地质特征进行直接的观察,配合其他海底勘查装备可实现探测对象的定点探测和采样,从而大大提高海底地质勘查的能力和效果,提高工作效率。不同的视频编码方式,直接影响图像清晰度、数据存储量及稳定性,文章介绍了MPEG4在海底彩色电视监控系统中应用的成功经验。