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Diaz, Vitali (author), van Oosterom, P.J.M. (author), Meijers, B.M. (author), Verbree, E. (author), Ahmed, N. (author), Van Lankveld, T. (author)Cloud-to-cloud (C2C) distance calculations are frequently performed as an initial stage in change detection and spatiotemporal analysis with point clouds. There are various methods for calculating C2C distance, also called inter-point distance, which refers to the distance between two corresponding point clouds captured at different epochs....conference paper 2024
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Zhang, Xiang (author), Touya, Guillaume (author), Meijers, B.M. (author)Automated map generalization has been a major area of research for decades but has still not reached maturity. Besides the needs for more adaptive algorithms, a fundamental question remains: How can we transfer human generalization knowledge into a computational system more effectively? Previous efforts do not seem capable to fully overcome the ...contribution to periodical 2024
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Peng, D.L. (author), Meijers, B.M. (author), van Oosterom, P.J.M. (author)When users zoom in or out on a digital map, the map should change correspondingly to present geographical information at proper levels. A way to help map users better keep track of their interested objects is to change the map smoothly instead of discretely switching between several levels of detail. This paper focuses on the problem of...journal article 2023
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Diaz, Vitali (author), Liu, H. (author), van Oosterom, P.J.M. (author), Meijers, B.M. (author), Verbree, E. (author), Baart, F. (author), Pronk, M.J. (author), Van Lankveld, T. (author)Point cloud is made up of a multitude of three-dimensional (3D) points with one or more attributes attached. Point cloud is the third data paradigm in addition to the well-established object (vector) and gridded (raster) representations, since point cloud data can be directly collected, computed, stored, and analyzed without converting to other...conference paper 2022
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- Meijers, B.M. (author), van Oosterom, P.J.M. (author) abstract 2022
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van Oosterom, P.J.M. (author), van Oosterom, S.J.M. (author), Liu, Haicheng (author), Thompson, R.J. (author), Meijers, B.M. (author), Verbree, E. (author)Point clouds contain high detail and high accuracy geometry representation of the scanned Earth surface parts. To manage the huge amount of data, the point clouds are traditionally organized on location and map-scale; e.g. in an octree structure, where top-levels of the tree contain few points suitable for small scale overviews and lower...journal article 2022
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Meijers, B.M. (author)We investigate how PCServe, a web service for disseminating massive point clouds, performs for read-only access (i.e. a visualization application). PCServe is backed by a database model based on Space Filling Curves. By adding a virtual hierarchy of blocks to the database, we can support different visualization applications for retrieval of...journal article 2022
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Alattas, A.F.M. (author), de Vries, M.E. (author), Meijers, B.M. (author), Zlatanova, Sisi (author), van Oosterom, P.J.M. (author)A web-based application has been developed, exploiting the integrated model of LADM andIndoorGML to provide indoor navigation based on the user's access rights in an educationalbuilding. Different types of users (students, teachers, visitors, etc.) have different access rights,which also depend on the exact time (e.g. inside or outside office...conference paper 2021
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- Altan, Yigit Can (author), Meijers, B.M. (author) conference paper 2021
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Liu, H. (author), Thompson, R.J. (author), van Oosterom, P.J.M. (author), Meijers, B.M. (author)As an extension to 2D polygonal queries, the nD-polytope queries on point clouds also play a crucial rolein nD GIS applications such as the perspective view selection. This report rst denes the nD-polytopemathematically, and then develops an ecient nD-polytope querying solution by extending an index-organized table (IOT) approach. The solution...report 2021
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Liu, H. (author), Thompson, R.J. (author), van Oosterom, P.J.M. (author), Meijers, B.M. (author)Efficient spatial queries are frequently needed to extract useful information from massive nD point clouds. Most previous studies focus on developing solutions for orthogonal window queries, while rarely considering the polytope query. The latter query, which includes the widely adopted polygonal query in 2D, also plays a critical role in...journal article 2021
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Lumban-Gaol, Y. A. (author), Chen, Z. (author), Smit, M. (author), Li, X. (author), Erbaşu, M. A. (author), Verbree, E. (author), Balado Frías, J. (author), Meijers, B.M. (author), van der Vaart, C.G. (author)Point cloud data have rich semantic representations and can benefit various applications towards a digital twin. However, they are unordered and anisotropically distributed, thus being unsuitable for a typical Convolutional Neural Networks (CNN) to handle. With the advance of deep learning, several neural networks claim to have solved the...journal article 2021
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Liu, H. (author), van Oosterom, P.J.M. (author), Mao, B. (author), Meijers, B.M. (author), Thompson, R. (author)Governments use flood maps for city planning and disaster management to protect people and assets. Flood risk mapping projects carried out for these purposes generate a huge amount of modelling results. Previously, data submitted are highly condensed products such as typical flood inundation maps and tables for loss analysis. Original...journal article 2021
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Peng, D.L. (author), Meijers, B.M. (author), van Oosterom, P.J.M. (author)When users zoom out on a digital map, some area objects become too tiny to be seen, resulting in visual clutters. To avoid this problem, the relatively unimportant areas should be merged with their neighbors to form larger<br/>areas. In order to provide small and smooth changes so that users can easily keep their contexts, we merge a pair of...conference paper 2020
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Opstal, Willem van (author), Meijers, B.M. (author), Peters, R.Y. (author)Navigational charts play a vital role in a ship's safety while navigating the seas, rivers or lakes. With most of the features and obstructions being out of sight -below sea-level - these charts are more critical than e.g. topographic maps. For routing but also positioning, depth information is a key aspect on these charts. This depth...conference paper 2020
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Peng, D.L. (author), Meijers, B.M. (author), van Oosterom, P.J.M. (author)This paper presents a web map juxtaposition comparer. Using the comparer, we can place two maps side by side for comparison. The maps of the comparer can contain multiple layers, and each of them can be a multi-scale layer<br/>or a vario-scale layer. We enhance the comparer’s visual analytical ability by developing more functionalities,...conference paper 2020
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Liu, H. (author), van Oosterom, P.J.M. (author), Meijers, B.M. (author), Guan, Xuefeng (author), Verbree, E. (author), Horhammer, Mike (author)Space Filling Curve (SFC) mapping-based clustering and indexing works effectively for point clouds management and querying. It maps both points and queries into a one-dimensional SFC space so that B+- tree could be utilized. Based on the basic structure, this paper develops a generic HistSFC approach which utilizes a histogram tree recording...journal article 2020
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Meijers, B.M. (author), van Oosterom, P.J.M. (author), Driel, Mattijs (author), Suba, R. (author)The Space-Scale Cube (SSC) model stores the result of a generalization process, that supports smooth scale transitions for map objects. The third dimension is used to describe geometrically the smooth transitions between objects at different levels of detail. Often-used map generalization operators fit in this SSC model. The 3D SSC model to...journal article 2020
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Balado, Jesús (author), van Oosterom, P.J.M. (author), Díaz-Vilarino, L. (author), Meijers, B.M. (author)Many of the point cloud processing techniques have their origin in image processing. But mathematical morphology, despite being one of the most used image processing techniques, has not yet been clearly adapted to point clouds. The aim of this work is to design the basic operations of mathematical morphology applicable to 3D point cloud data,...journal article 2020
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Liu, H. (author), van Oosterom, P.J.M. (author), Meijers, B.M. (author), Verbree, E. (author)Dramatically increasing collection of point clouds raises an essential demand for highly efficient data management. It can also facilitate modern applications such as robotics and virtual reality. Extensive studies have been performed on point data management and querying, but most of them concentrate on low dimensional spaces. High...journal article 2020