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Texture mapping generates photorealistic representations of three‐dimensional (3D) geometric objects and enhances the spatial perception of areas of interest. Over the past two decades, even though various approaches for 3D urban models have been investigated, their use has been limited because of the lack of spatial accuracy, details, and the complex processes. It is difficult to maintain highly detailed texture information without using a hybrid of aerial image and ground‐based imaging techniques, which are costly. Furthermore, it is hard to develop a fully automated process for 3D urban mapping that achieves high spatial accuracy. With regard to the issues, this research aims to develop a semi‐automated process for 3D building models that would help image‐based approaches. It helps acquire qualified texture information and improve the appearance of building façades in a large city. In particular, this research first investigates an optimal overlap of consecutive aerial images that generates sufficient information to texture each façade, thus making this process more cost‐effective. Second, this research develops an application to semi‐automatically build 3D buildings and textured 3D buildings. The application is developed in C++. The textured 3D building models are quantitatively and qualitatively assessed to determine the usability of the semi‐automated process. 相似文献
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City model enrichment 总被引：1，自引：0，他引：1
Philip D. Smart Jonathan A. Quinn Christopher B. Jones 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(2):223-234
The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods. 相似文献
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Due to the fast development of the urban environment, the need for efficient maintenance and updating of 3D building models is ever increasing. Change detection is an essential step to spot the changed area for data (map/3D models) updating and urban monitoring. Traditional methods based on 2D images are no longer suitable for change detection in building scale, owing to the increased spectral variability of the building roofs and larger perspective distortion of the very high resolution (VHR) imagery. Change detection in 3D is increasingly being investigated using airborne laser scanning data or matched Digital Surface Models (DSM), but rare study has been conducted regarding to change detection on 3D city models with VHR images, which is more informative but meanwhile more complicated. This is due to the fact that the 3D models are abstracted geometric representation of the urban reality, while the VHR images record everything. In this paper, a novel method is proposed to detect changes directly on LOD (Level of Detail) 2 building models with VHR spaceborne stereo images from a different date, with particular focus on addressing the special characteristics of the 3D models. In the first step, the 3D building models are projected onto a raster grid, encoded with building object, terrain object, and planar faces. The DSM is extracted from the stereo imagery by hierarchical semi-global matching (SGM). In the second step, a multi-channel change indicator is extracted between the 3D models and stereo images, considering the inherent geometric consistency (IGC), height difference, and texture similarity for each planar face. Each channel of the indicator is then clustered with the Self-organizing Map (SOM), with “change”, “non-change” and “uncertain change” status labeled through a voting strategy. The “uncertain changes” are then determined with a Markov Random Field (MRF) analysis considering the geometric relationship between faces. In the third step, buildings are extracted combining the multispectral images and the DSM by morphological operators, and the new buildings are determined by excluding the verified unchanged buildings from the second step. Both the synthetic experiment with Worldview-2 stereo imagery and the real experiment with IKONOS stereo imagery are carried out to demonstrate the effectiveness of the proposed method. It is shown that the proposed method can be applied as an effective way to monitoring the building changes, as well as updating 3D models from one epoch to the other. 相似文献
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3D city models offered by digital map providers typically consist of several thousands or even millions of individual buildings. Those buildings are usually generated in an automated fashion from high resolution cadastral and remote sensing data and can be very detailed. However, not in every application such a high degree of detail is desirable. One way to remove complexity is to aggregate individual buildings, simplify the ground plan and assign an appropriate average building height. This task is computationally complex because it includes the combinatorial optimization problem of determining which subset of the original set of buildings should best be aggregated to meet the demands of an application.In this article, we introduce approaches to express different aspects of the aggregation of LoD 1 building models in the form of Mixed Integer Programming (MIP) problems. The advantage of this approach is that for linear (and some quadratic) MIP problems, sophisticated software exists to find exact solutions (global optima) with reasonable effort. We also propose two different heuristic approaches based on the region growing strategy and evaluate their potential for optimization by comparing their performance to a MIP-based approach. 相似文献
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利用机载LiDAR点云数据进行建筑物重建是当今摄影测量与遥感领域的一个热点问题,特别是复杂形状建筑物模型的精确自动构建一直是一个难题。本文提出一种基于关键点检测的复杂建筑物模型自动重建方法,采用RANSAC法与距离法相结合的分割方法自动提取建筑物屋顶各个平面的点云,并利用Alpha Shape算法提取出各个平面的精确轮廓,根据屋顶平面之间的空间拓扑关系分析建筑物的公共交线特征,在此特征约束下对提取的初始关键点进行修正,最终重建出精确的建筑物3维模型。选取不同类型复杂建筑物与包含复杂建筑物的城市区域点云进行实验,结果表明该算法具有较强实用价值。 相似文献
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Youness Dehbi Fabian Hadiji Gerhard Gröger Kristian Kersting Lutz Plümer 《Transactions in GIS》2017,21(1):134-150
The automatic interpretation of 3D point clouds for building reconstruction is a challenging task. The interpretation process requires highly structured models representing semantics. Formal grammars can describe structures as well as the parameters of buildings and their parts. We propose a novel approach for the automatic learning of weighted attributed context‐free grammar rules for 3D building reconstruction, supporting the laborious manual design of rules. We separate structure from parameter learning. Specific Support Vector Machines (SVMs) are used to generate a weighted context‐free grammar and predict structured outputs such as parse trees. The grammar is extended by parameters and constraints, which are learned based on a statistical relational learning method using Markov Logic Networks (MLNs). MLNs enforce the topological and geometric constraints. MLNs address uncertainty explicitly and provide probabilistic inference. They are able to deal with partial observations caused by occlusions. Uncertain projective geometry is used to deal with the uncertainty of the observations. Learning is based on a large building database covering different building styles and façade structures. In particular, a treebank that has been derived from the database is employed for structure learning. 相似文献
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随着三维激光点云数据获取能力的提升，基于三维激光点云进行建筑物模型重建与立面测绘成为工程应用中常用的方法。三维激光点云数据能够体现建筑物丰富和直观的细节信息，然而海量数据处理给建筑物模型构建带来了极大挑战。本文通过对建筑物的三维激光点云数据进行横切得到建筑物轮廓点，并采用基于遗传算法的TSP算法对轮廓点进行处理以获取建筑物各立面的方程系数，最终实现建筑物模型的构建和获取详细的建筑物立面数据。试验结果表明，此方法可以较好地实现LOD1级建筑物模型的构建，进而为更高（LOD3）级别的建筑物模型构建提供依据。 相似文献
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Jochen Meidow Christian Beder Wolfgang Förstner 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(2):125-139
Decisions based on basic geometric entities can only be optimal, if their uncertainty is propagated through the entire reasoning chain. This concerns the construction of new entities from given ones, the testing of geometric relations between geometric entities, and the parameter estimation of geometric entities based on spatial relations which have been found to hold.Basic feature extraction procedures often provide measures of uncertainty. These uncertainties should be incorporated into the representation of geometric entities permitting statistical testing, eliminates the necessity of specifying non-interpretable thresholds and enables statistically optimal parameter estimation. Using the calculus of homogeneous coordinates the power of algebraic projective geometry can be exploited in these steps of image analysis.This review collects, discusses and evaluates the various representations of uncertain geometric entities in 2D together with their conversions. The representations are extended to achieve a consistent set of representations allowing geometric reasoning. The statistical testing of geometric relations is presented. Furthermore, a generic estimation procedure is provided for multiple uncertain geometric entities based on possibly correlated observed geometric entities and geometric constraints. 相似文献
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三维建模技术能够实现建筑物的数字化存档，在古建筑保护与修复和现代建筑规划与改造中具有不可替代的作用。针对倾斜摄影测量和三维激光扫描建模技术中建筑物模型存在的问题，本文提出了一种倾斜摄影测量和三维激光扫描生成三维点云模型相融合的建筑物精细化建模方法。选用无人机和三维激光扫描仪作为试验设备，利用ContextCapture、SCENE软件完成点云拼接、生产和编辑，通过ICP算法完成点云精细匹配，实现多源点云数据融合建模；对比单一建模方法模型，从纹理结构和模型精度两方面对融合建模模型进行质量评价。结果表明，融合建模模型纹理清晰，几何结构完整，模型距离中误差和高差中误差的均值均低于倾斜摄影测量模型的值，接近三维激光扫描模型。 相似文献
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建筑物的三维建模是城市三维建模和可视化的重要组成部分。本文提出一种基于点云数据与遥感图像的建筑物三维模型快速建模方法。首先,运用改进的RANSAC法从点云数据中提取建筑立面,根据立面区分平顶建筑与人字形屋顶建筑;在此基础上,进一步对建筑物的高度进行提取;之后,利用区域增长法从遥感图像中提取建筑物屋顶轮廓,利用形态学方法对提取出的轮廓进行规则化处理,并基于Freeman链码提取轮廓角点,得到规整的轮廓;最后,根据提取出的建筑高度属性对屋顶轮廓拉伸并进行纹理映射,实现对建筑物的三维重建。通过实例证明,提出的方法能快速、高效地实现建筑物三维模型的重建。 相似文献
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一种利用影像匹配的城区三维景观图生成途径 总被引：1，自引：0，他引：1
提出了一种基于影像匹配的城区三维景观图生成方法,它首先利用神经网络影像匹配得出城区的密集视差表面,再利用基于模板匹配的半自动建筑物提取方法获得建筑物的关量数据和高程,进而得出城区三维数字模型,从而获得真实的城区三维透视景观图。 相似文献
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针对城市侧视地图上建筑物轮廓线主要依靠人工交互提取,成本高昂、效率低下且精细度和准确度有限的问题,提出了一种任意视角侧视地图中建筑物轮廓线的自动提取方法。采用深度缓冲区分割算法获取单个建筑物对象的颜色缓冲区,顾及了存在建筑群的情况和建筑物密集区域的遮挡问题,再基于颜色缓冲区追踪建筑物轮廓线。为了保持遮挡一致性且便于匹配提取出的矢量轮廓线与栅格侧视地图,本文还提出了基于投影空间分块加载三维城市模型的方法。最后,以武汉市典型三维城市模型数据为例,证明了该方法的有效性和可靠性。 相似文献
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Three-dimensional (3-D) representations of urban regions have gained much attention because of recent developments in remote sensing and computer graphics technologies. In particular, textured 3-D building reconstruction for a variety of applications has been a popular research topic in recent years. In this study, we present the reconstruction of 3-D building models along with texture selection and mapping. Extracted two-dimensional building patches and normalized digital surface model (nDSM) data are used to generate the 3-D models. To build near-photorealistic 3-D models, the acquired geo-referenced facade textures are associated with the corresponding building facades using an automated GPS-assisted approach. On the other hand, the modelling and texture mapping of the roof structures were carried out manually. The study area is composed of eight housing estates (blocks), where a total of 110 buildings were analysed. The whole study area was modelled, with facade textures, in less than 1 min of processor running time with an acceptable level of accuracy. The texture mapping was carried out using MATLAB’s Virtual Reality Toolbox?. 相似文献
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本文从空间-语义双重约束角度,提出一种顾及空间邻近和功能语义相似的建筑物空间分布模式识别方法。首先,基于建筑物的空间位置邻近性(即建筑物间的最小距离)约束进行聚类,获得建筑物的空间分布模式和建筑物间的空间邻近关系;然后,根据建筑物的功能语义相似性约束进行分割,获得建筑物的初步聚类结果;最后,考虑簇内相似性与簇间差异性进行整体优化,获得最终聚类结果。试验验证表明,本文方法比现有方法能够更有效地识别空间邻近与功能语义一致的建筑物群,服务于智慧城市建设中对建筑物进行语义层次综合和对城市结构进行深入研究的需求。 相似文献
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针对现有建筑物多细节层次（level of detail,LOD）表达主要面向外部,很少涉及内部空间的问题,提出一种含室内空间结构的建筑物三维LOD概念模型。该模型分为LOD0~LOD6 7个LOD,细节层次由建筑物的基底平面图、幢模型、无侧面楼层模型、楼层模型、户模型、房间模型到含门、窗等建筑语义的信息房间模型,空间细节逐次变细,丰富了建筑物室内空间LOD的表达理论。为构建这种LOD模型,提出基于胞腔复形链边界算子和上边界算子的LOD生成方法。该方法引入代数拓扑的胞腔、胞腔复形和复形链3个概念,利用胞腔和胞腔复形表达LOD,并在LOD6的基础上,利用边界算子和上边界算子生成其他粗空间粒度LOD模型,为三维城市模型建筑物LOD构建提供一种新方法。 相似文献
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多因子影响的地图居民地自动聚群与综合研究 总被引：1，自引：0，他引：1
提出了地图综合目的的居民地聚群需要遵循Gestalt的邻近性、相似性和方向性原则,描述居民地结构、形态及其关系需要6个因子,即居民地间的距离、可视区域面积、大小相似度、形状相似度、方向关系、居民地内部方向;进而运用这些原则和因子,给出了居民地的自动聚群和综合方法. 相似文献