Filters








319,674 Hits in 8.2 sec

A system of types and operators for handling vague spatial objects

Arta Dilo, Rolf A. de By, Alfred Stein
2007 International Journal of Geographical Information Science  
They are regularized fuzzy set operators: union, intersection, and difference; two operators from topology: boundary and frontier; and two operators on vague partitions: overlay and fusion.  ...  The paper is illustrated with an application of vague objects in coastal erosion.  ...  Acknowledgements The work was funded by the European Community, under IST-1999-14189 project REV!GIS. The datasets were made available by Rijkswaterstaat and RIKZ.  ... 
doi:10.1080/13658810601037096 fatcat:z5jplui7frbftj2ld2vqzcuatm

A Completeness of Metrics for Topological Relations in 3D Qualitative Spatial Reasoning

Chaman L. Sabharwal, Jennifer L. Leopold
2015 POLIBITS Research Journal on Computer Science and Computer Engineering With Applications  
Here we present an exposition for 3D objects. There are three types of binary relations between pairs of objects: topological connectivity, cardinal directions, and distance relations.  ...  The complete set of metrics that we present should be useful for a variety of applications dealing with 3D objects including regions with vague boundaries.  ...  Also we will explore the applications of these metrics between heterogeneous dimension objects, OmR m and OnR n for m, n {1,2,3}. Fig. 1 .Fig. 2 . 12 Two examples of disjoint objects.  ... 
doi:10.17562/pb-52-1 fatcat:arkcy5jvofdehbzrro5pto7yjy

A comprehensive process of reverse engineering from 3D meshes to CAD models

Roseline Bénière, Gérard Subsol, Gilles Gesquière, François Le Breton, William Puech
2013 Computer-Aided Design  
Fig. 9 . 9 (a) Extended areas based on Point areas and primitives, (b) Common points, (c) Adjacency graph (one node per primitive and an edge if the two primitives are adjacent), (d) Intersections between  ...  In Fig. 9(d) , the set of all intersection curves between geometric primitives is presented.  ... 
doi:10.1016/j.cad.2013.06.004 fatcat:igwpgp7nmff53pugs6yho2p4xm

MULTI-DIMENSIONAL QUALITY ASSESSMENT OF PHOTOGRAMMETRIC AND LIDAR DATASETS BASED ON A VECTOR APPROACH

M. Mohamed, T. Landes, P. Grussenmeyer, W. Zhang
2013 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
Intersection volume is defined by superimposing the building model to be tested with the reference one.  ...  Quality of the planes under study is assessed by calculating a set of indices in vector format. For 3D assessment, building models are considered as one object.  ...  it is the ratio between the ρd = Ar∩At Ar intersection area between two planes and the ρd ∈ [0 : 1] reference plane. ρd = 1 means that the calculated polygon is perfectly superposed Quality rate: it is  ... 
doi:10.5194/isprsarchives-xl-2-w1-93-2013 fatcat:wo3lxv4yd5hdpptxgjrhvdkug4

Concave Hull of a Set of Freeform Closed Surfaces inR3

A. V. Vishwanath, M. Ramanathan
2012 Computer-Aided Design and Applications  
Based on this observation, a conjecture is proposed for elements in the concave hull of freeform closed objects in n dimensions.  ...  Recently, we approached the question of bounding hull to a set of close planar freeform curves and proposed an algorithm for concave hull by defining it (definition was lacking even for a point-set).  ...  Lemma 1 The distance between two closed C 1 non-intersecting surfaces is minimum only when the normals of the corresponding points are opposite to each other (i.e., antipodal).  ... 
doi:10.3722/cadaps.2012.857-868 fatcat:y6znp35mtra7hepau2mtxftaxe

An algorithm for 3D shape matching using spherical sectioning

Jaeho Lee, Joonyoung Park, Hyunchan Lee
2006 Journal of Zhejiang University: Science A  
We show the experimental results for the validity of our method.  ...  The SSRD (spherical sectioning railroad diagram) algorithm has the general shape distribution's properties and overall features of the original model. The SSRD's useful properties are discussed.  ...  Since we can obtain the closed loops from the model's rotational intersection planes, we can take the number of closed loop and common occupation area between each closed loops of two models.  ... 
doi:10.1631/jzus.2006.a1508 fatcat:eizsnkswbzcpno2i56g47gbg3u

Metric details for natural-language spatial relations

Max J. Egenhofer, A. Rashid B. M. Shariff
1998 ACM Transactions on Information Systems  
Two groups of metric details are derived: splitting ratios as the normalized values of lengths and areas of intersections; and closeness measures as the normalized distances between disjoint object parts  ...  Three examples demonstrate how the framework and its calibrated values are used to determine the best spatial term for a relationship between two geometric objects.  ...  established by one of the two objects' orientations.  ... 
doi:10.1145/291128.291129 fatcat:fetr7lwtzvb33dg4m6q2brtbiy

Spatial Operations

Anda VELICANU
2010 Database Systems Journal  
on the map or analysis on grid cells.  ...  This paper contains a brief description of the most important operations that can be performed on spatial data such as spatial queries, create, update, insert, delete operations, conversions, operations  ...  Aknowledgement This article is a result of the project "Doctoral Program and PhD Students in the education research and innovation triangle". This project is co funded by European Social  ... 
doaj:6164db1155c44ac382662eec198e1dec fatcat:b4n5zpqsqfgz5fjml5uzxjsnpm

Qualitative Spatial-Relation Reasoning for Design [chapter]

Max J. Egenhofer
2014 Studying Visual and Spatial Reasoning for Design Creativity  
The abstract representation of the relations' interconnectedness in the form of their conceptual neighborhood graphs offers intriguing insight about the regularity of such complete sets of qualitative  ...  This paper compiles some of the most commonly used sets of qualitative spatial relations and their logical inference mechanisms.  ...  EC = area(Δ (A )) area(A ) + area(Δ (A )) The two closeness measures (a) Expansion Closeness (EC) and (b) Contraction Closeness (CC) (Egenhofer and Dube 2009).  ... 
doi:10.1007/978-94-017-9297-4_9 fatcat:4pacagpgyvbxdgzwdoz55o7pxe

Measuring shape relations using r-parallel sets [article]

Hans JT Stephensen, Anne Marie Svane, Carlos Benitez, Steven A. Goldman, Jon Sporring
2020 arXiv   pre-print
Our theory is based on the relation between two objects: a reference and an observed object.  ...  We generate the r-parallel sets of the reference object, we calculate the intersection between the r-parallel sets and the observed object, and we define measures on these intersections.  ...  We extend the notion of distance as the shortest distance between two objects.  ... 
arXiv:2008.03927v1 fatcat:7tjqvaaal5aklnzzkzcsarmk4a

Functional object descriptors for human activity modeling

Alessandro Pieropan, Carl Henrik Ek, Hedvig Kjellstrom
2013 2013 IEEE International Conference on Robotics and Automation  
The similarity between two such object descriptors can be measured using a string kernel.  ...  Object models designed for this purpose should reflect the role of the object in the activity -its function, or affordances.  ...  This research has been supported by the EU through TOMSY, IST-FP7-Collaborative Project-270436, and the Swedish Research Council (VR).  ... 
doi:10.1109/icra.2013.6630736 dblp:conf/icra/PieropanEK13 fatcat:b4mxkbmwnjfldlkvvh3ynrouvu

Homotopic Object Reconstruction Using Natural Neighbor Barycentric Coordinates

Ojaswa Sharma, François Anton
2010 2010 International Symposium on Voronoi Diagrams in Science and Engineering  
One of the challenging problems in computer vision is object reconstruction from cross sections.  ...  These allow us to formulate homotopies on edges of the polygons from which the underlying object can be reconstructed.  ...  of the two areas and the area of the object.  ... 
doi:10.1109/isvd.2010.19 dblp:conf/isvd/SharmaA10 fatcat:s5ps6fskdnbfxdyiej6cjrx6qq

Experiments and Analysis of Close-Shot Identification of On-Branch Citrus Fruit with RealSense

Jizhan Liu, Yan Yuan, Yao Zhou, Xinxin Zhu, Tabinda Syed
2018 Sensors  
This method effectively utilizes depth-point cloud data in a close-shot range of 160 mm and different geometric features of the fruit and leaf to recognize fruits with a intersection curve cut by the depth-sphere  ...  The size of the fruit has a more noticeable impact on the success rate of detection.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/s18051510 pmid:29751594 pmcid:PMC5982123 fatcat:sx6klgphdfg43kyyxy5lkms2ru

Homotopic Object Reconstruction Using Natural Neighbor Barycentric Coordinates [chapter]

Ojaswa Sharma, François Anton
2011 Lecture Notes in Computer Science  
One of the challenging problems in computer vision is object reconstruction from cross sections.  ...  These allow us to formulate homotopies on edges of the polygons from which the underlying object can be reconstructed.  ...  of the two areas and the area of the object.  ... 
doi:10.1007/978-3-642-25249-5_8 fatcat:zxsy2q6oafbfjfakhrez5pzuim

Two-Layer Tracking For Occlusion Handling And Inter-Sensor Identification In Multiple Depth Sensors-Based Object Detection And Tracking

Sei Naito, Houari Sabirin
2018 Zenodo  
Publication in the conference proceedings of EUSIPCO, Kos island, Greece, 2017  ...  To determine that the intersect indicates an occlusion, two conditions apply: 1) the intersect areas of 1 A respectively, shall be larger than a given threshold; and 2) at least two areas are intersecting  ...  Here d  is defined as the set of depth value that satisfies       j i j i j i D f , 2 , ,     in all F frames, and d  as the set of depth value differences for each pixels between two consecutive  ... 
doi:10.5281/zenodo.1159466 fatcat:jgu3ugdxs5cz7hqcldzodqgdey
« Previous Showing results 1 — 15 out of 319,674 results