Centre de documentation
scientifique

Patch-based detection of dynamic objects in CrowdCam images / Gagan Kanojia in The Visual Computer, vol 35 n° 4 (April 2019)  

Public [article]  inThe Visual Computer > vol 35 n° 4 (April 2019) . - pp 521 - 534 Titre : Patch-based detection of dynamic objects in CrowdCam images Type de document : Article/Communication Auteurs : Gagan Kanojia, Auteur ; Shanmuganathan Raman, Auteur Année de publication : 2019 Article en page(s) : pp 521 - 534 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] compréhension de l'image [Termes IGN] détection d'objet [Termes IGN] géométrie épipolaire [Termes IGN] objet mobile [Termes IGN] objet statique Résumé : (auteur) A scene can be divided into two parts: static and dynamic. The parts of the scene which do not admit any motion are static regions, while moving objects correspond to dynamic regions. In this work, we tackle the challenging task of identifying dynamic objects present in the CrowdCam images. Our approach exploits the coherency present in the natural images and utilizes the epipolar geometry present between a pair of images to achieve this objective. It does not require a dynamic object to be present in all the given images. We show that the proposed approach obtains state-of-the-art accuracy on standard datasets. Numéro de notice : A2019-120 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00371-018-1480-3 Date de publication en ligne : 06/02/2018 En ligne : https://doi.org/10.1007/s00371-018-1480-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92442 [article]

Point clouds for direct pedestrian pathfinding in urban environments / Jesus Balado in ISPRS Journal of photogrammetry and remote sensing, vol 148 (February 2019)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 148 (February 2019) . - pp 184 - 196 Titre : Point clouds for direct pedestrian pathfinding in urban environments Type de document : Article/Communication Auteurs : Jesus Balado, Auteur ; Lucia Diaz-Vilarino, Auteur ; Pedro Arias, Auteur ; Henrique Lorenzo, Auteur Année de publication : 2019 Article en page(s) : pp 184 - 196 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] accessibilité [Termes IGN] chemin le plus court, algorithme du [Termes IGN] détection de partie cachée [Termes IGN] données localisées 3D [Termes IGN] graphe [Termes IGN] itinéraire piétionnier [Termes IGN] milieu urbain [Termes IGN] navigation pédestre [Termes IGN] objet mobile [Termes IGN] objet statique [Termes IGN] semis de points Mots-clés libres : espace urbain navigable pour piéton Résumé : (Auteur) Pathfinding applications for the citizen in urban environments are usually designed from the perspective of a driver, not being effective for pedestrians. In addition, urban scenes have multiple elements that interfere with pedestrian routes and navigable space. In this paper, a methodology for the direct use of point clouds for pathfinding in urban environments is presented, solving the main limitations for this purpose: (a) the excessive number of points is reduced for transformation into nodes on the final graph, (b) urban static elements acting as permanent obstacles, such as furniture and trees, are delimited and differentiated from dynamic elements such as pedestrians, (c) occlusions on ground elements are corrected to enable a complete graph modelling, and (d) navigable space is delimited from free unobstructed space according to two motor skills (pedestrians without reduced mobility and wheelchairs). The methodology is tested into three different streets sampled as point clouds by mobile laser scanning (MLS) systems: an intersection of several streets with ground composed of sidewalks at different heights; an avenue with wide sidewalks, trees and cars parked on one side; and a street with a single-lane road and narrow sidewalks. By applying Dijkstra pathfinding algorithm to the resulting graphs, the correct viability of the generated routes has been verified based on a visual analysis of the generated routes on the point cloud and on the knowledge of the urban study area. The methodology enables the automatic generation of graphs representing the navigable urban space, on which safe and real routes for different motor skills can be calculated. Numéro de notice : A2019-074 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.01.004 Date de publication en ligne : 15/01/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.01.004 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92161 [article]

Exemplaires(3)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-2019021	RAB	Revue	Centre de documentation	En réserve L003	Disponible
081-2019023	DEP-RECP	Revue	LASTIG	Dépôt en unité	Exclu du prêt
081-2019022	DEP-RECF	Revue	Nancy	Dépôt en unité	Exclu du prêt

Algorithms for nearest neighbor search on moving object trajectories / E. Frentzos in Geoinformatica, vol 11 n° 2 (June - August 2007)  

Public [article]  inGeoinformatica > vol 11 n° 2 (June - August 2007) . - pp 159 - 193 Titre : Algorithms for nearest neighbor search on moving object trajectories Type de document : Article/Communication Auteurs : E. Frentzos, Auteur ; K. Gratsias, Auteur ; Nikos Pelekis, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 159 - 193 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] arbre-R [Termes IGN] base de données d'objets mobiles [Termes IGN] classification barycentrique [Termes IGN] continuité géographique [Termes IGN] distance euclidienne [Termes IGN] objet mobile [Termes IGN] objet statique [Termes IGN] spatial metrics Résumé : (Auteur) Nearest Neighbor (NN) search has been in the core of spatial and spatiotemporal database research during the last decade. The literature on NN query processing algorithms so far deals with either stationary or moving query points over static datasets or future (predicted) locations over a set of continuously moving points. With the increasing number of Mobile Location Services (MLS), the need for effective k-NN query processing over historical trajectory data has become the vehicle for data analysis, thus improving existing or even proposing new services. In this paper, we investigate mechanisms to perform NN search on R-tree-like structures storing historical information about moving object trajectories. The proposed (depth-first and best-first) algorithms vary with respect to the type of the query object (stationary or moving point) as well as the type of the query result (historical continuous or not), thus resulting in four types of NN queries. We also propose novel metrics to support our search ordering and pruning strategies. Using the implementation of the proposed algorithms on two members of the R-tree family for trajectory data (namely, the TB-tree and the 3D-R-tree), we demonstrate their scalability and efficiency through an extensive experimental study using large synthetic and real datasets. Copyright Springer Numéro de notice : A2007-236 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-006-0007-7 En ligne : https://doi.org/10.1007/s10707-006-0007-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28599 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-07021	RAB	Revue	Centre de documentation	En réserve L003	Disponible