基于天-空-地一体化的重大地质灾害隐患早期识别与监测预警

对公众展开滑坡灾害教育,可以提升公众的灾害风险意识。目前的灾害教育主要针对学生与救护人员,其教育方式集中于课本教学及专业培训,内容专业性较强,且教育者与公众之间缺乏有效的沟通渠道,公众难以对滑坡灾害有直观认知。针对上述问题,提出一种面向公众教育的滑坡灾害可视化视觉表征方法,重点研究动静结合的视觉表征框架以及滑坡灾害知识图解与概念图实例化等关键技术,以实现对滑坡过程的整体描述与外在因果的表现。选择2017年6月24日发生的6·24茂县叠溪特大山体滑坡开展案例实验分析,实验结果表明,该方法能够有效地构建滑坡灾害知识的视觉内容,快速地帮助公众了解滑坡灾害知识。     

三维GIS支持下的实景融合系统设计与实现

视频监控在安防领域的应用日益广泛,但传统的分镜头监控模式具有画面相互孤立、缺乏关联性的应用局限.针对这一问题本文分析了实时监控视频在三维场景中融合展示的难点问题,设计了基于三维GIS的实景融合系统.系统通过视觉特征匹配计算视频投射视角,针对球机设备研究了虚实场景视频联动投射的方法,并通过服务化配置的方式进行数据的加载....     

Multiresolution fusion of remote sensing images based on resolution degradation model

A new method based on resolution degradation model is proposed to improve both spatial and spectral quality of the synthetic images. Some ETM panchromatic and multispectral images are used to assess the new method. Its spatial and spectral effects are evaluated by qualitative and quantitative measures and the results are compared with those of IHS, PCA, Brovey, OWT(Orthogonal Wavelet Transform) and RWT (Redundant Wavelet Transform). The results show that the new method can keep almost the same spatial resolution as the panchromatic images, and the spectral effect of the new method is as good as those of waveletbased methods.     

Integration of 3DGIS and BIM and its application in visual detection of concealed facilities

The multi-level modeling technology of Building Information Modeling(BIM),combined with Three-dimensional Geographic Information System(3DGIS)macro-scene visualization technol-ogy and location information,can realize the transmission of decentralized information from various disciplines to multi-disciplinary collaborative information sharing services.It can be applied independently for the whole life cycle,which plays a positive role in reducing the cost and improving the efficiency of engineering planning,design,construction,operation,and maintenance.In this paper,the data integration and function integration methods of 3DGIS and BIM are designed.In order to avoid the breaking problems caused by attribute information loss and excessive simplification in the process of BIM data integration,the attribute mapping between 3DGIS and BIM based on Industry Foundation Classes(IFC)and City Geography Markup Language(CityGML)and the data simplification method considering the geometric character-istics of BIM are designed.By setting the relevant preconditions and thresholds of patch merging,on the premise of maintaining the structural characteristics of BIM data surface,reduce the amount of model data to improve the efficiency of BIM data loading,rendering and display effect in 3D geospatial scene.Through the data and function integration of 3DGIS and BIM,we can effectively manage the data of large-scale model,and calculate and obtain the geospatial location and direction of key parts of buildings through the coordinate transformation of BIM,which can effectively assist the rapid and accurate positioning of BIM in virtual 3D scene and expand the visualization ability of 3DGIS.By effectively integrating 3DGIS and BIM,this paper gives full play to the spatial management advantages of 3DGIS and the component management advantages of BIM.The rationality and operability of the method are verified by its application in the operation and maintenance management project of concealed facilities in actual buildings.     

一种双目直接法视觉里程计

视觉里程计是机器人确定自身在周围环境中位置的关键技术,具有测量漂移小、精确的特点,适合较长时间的自主定位.提出一种使用双目相机的直接法视觉里程计,使用双目影像对与时序影像对之间的光度误差联合优化关键帧的位置与姿态、相机内参数、地图点坐标,并在车载道路基准数据集KITTI上进行测试,获得了良好的效果.     

基于图像校准的多源融合的室内定位方法

提出一种基于图像校准的多源融合的室内定位方法。结合WiFi信号,图像及惯性传感器数据的特点,在空间连续性和方向连续性的基础上,设定一系列客观规则来提高定位精度,给出了多源融合的室内定位方法框架。试验结果表明：本方法在2m范围内匹配精度在85%以上,平均定位误差在2m精度范围内的准确率达到70%。通过与单纯使用WiFi或图像定位对比,该算法分别在速度和精度上得到了较大的提升。     

From physical space to visual image space

1　IntroductionVirtualreality (VR)isaformofhuman computerinterface(HCI) [1 ] .Andnowitisamajorbranchofcomputing ,cover ingabroadspectrumofhumaninteractionwithcomputers .Itrangesfromtheinteractionwithrealenvironmentstothatwithsyntheticallygeneratedworlds[2 ] .Usually ,intheinterac tiveprocess ,oneofthemainoutputsofcomputerisgraphicsonthescreen .Thegraphicsarethemaininformationsourcereceivedbyhumanfromthecomputers .Tohuman ,visionisthemostimportantorgantogaininformationfromthenaturalworld .S…     

保持视觉特征的lod模型简化算法研究

在考虑不严重影响画面视觉效果的前期下提出了保持视觉特征的lod模型简化算法该方法能较好地解决复杂地形场景模型引起的绘制视觉失真问题 在保持视觉特征的前提下引入顶点的曲度特征因子通过限制狭长三角形的生成和标记色差明显的三角形很好地保证了模型的几何和纹理特征 通过计算折叠代价的方法减少模型误差累积有效地解决了影响视觉效果的问题 实验结果表明在保证视觉特征的前提下利用半边折叠算法简化模型实现三维场景的地形绘制     

面向交通地理信息时空特征描述的Spatial-UML研究

空间信息系统建模的多样性、主流信息技术的高度集成性以及逐渐变复杂的系统体系都使得软件和数据库设计者向可视化建模的主流方向发展。分析面向地理信息时空特征描述而建立的空间可视化语言插件(SpatialPVLs),并基于可视化建模技术标准,应用统一建模语言(UML)内置的扩展机制实现了针对地理信息时空特征描述的扩展。UML和SpatialPVLs的集成过程定义了面向地理信息时空特征描述的可视化建模语言,即Spatial-UML。最后,以城市交通模拟地理信息系统(GIS)数据概念模型设计为实例,验证Spatial-UML的适用性和扩展性,建立一个可以满足不同领域用户访问和理解的互协作建模架构,实现交通地理对象的空间、时态和时空特征的可视化标准描述和表达。     

一种平面薄片零件单目视觉测量方法

针对传统的零件质量测量手段操作复杂、效率低等问题,该文提出基于大像幅非量测数码相机的单目视觉检测方法。首先基于二维直接线性变换和光束法平差进行相机内参数的标定;其次基于平面控制点信息进行单幅影像外方位元素的解算;然后进行影像的畸变纠正和垂直纠正;最后基于轮廓线的多特征提取方法求解零件特征参数等。将大像幅非量测数码相机用于较大平面薄片类零件检测的结果与三坐标量测仪的检测数据对比,实验结果表明,其量测误差小于0.1mm,满足较大幅平面薄片类零件尺寸量测的要求。