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Real-time web map construction based on multiple cameras and GIS / Xingguo Zhang in ISPRS International journal of geo-information, vol 10 n° 12 (December 2021)  

Public [article]  inISPRS International journal of geo-information > vol 10 n° 12 (December 2021) . - n° 803 Titre : Real-time web map construction based on multiple cameras and GIS Type de document : Article/Communication Auteurs : Xingguo Zhang, Auteur ; Xinyu Shi, Auteur ; Xiaoyue Luo, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 803 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] caméra vidéo numérique [Termes IGN] connecteur logiciel [Termes IGN] détection d'objet [Termes IGN] homologie [Termes IGN] système d'information géographique [Termes IGN] temps réel [Termes IGN] visualisation cartographique [Termes IGN] web mapping [Termes IGN] WebSIG Résumé : (auteur) Previous VideoGIS integration methods mostly used geographic homography mapping. However, the related processing techniques were mainly for independent cameras and the software architecture was C/S, resulting in large deviations in geographic video mapping for small scenes, a lack of multi-camera video fusion, and difficulty in accessing real-time information with WebGIS. Therefore, we propose real-time web map construction based on the object height and camera posture (RTWM-HP for short). We first consider the constraint of having a similar height for each object by constructing an auxiliary plane and establishing a high-precision homography matrix (HP-HM) between the plane and the map; thus, the accuracy of geographic video mapping can be improved. Then, we map the objects in the multi-camera video with overlapping areas to geographic space and perform the object selection with the multi-camera (OS-CDD) algorithm, which includes the confidence of the object, the distance, and the angle between the objects and the center of the cameras. Further, we use the WebSocket technology to design a hybrid C/S and B/S software framework that is suitable for WebGIS integration. Experiments were carried out based on multi-camera videos and high-precision geospatial data in an office and a parking lot. The case study’s results show the following: (1) The HP-HM method can achieve the high-precision geographic mapping of objects (such as human heads and cars) with multiple cameras; (2) the OS-CDD algorithm can optimize and adjust the positions of the objects in the overlapping area and achieve a better map visualization effect; (3) RTWM-HP can publish real-time maps of objects with multiple cameras, which can be browsed in real time through point layers and hot-spot layers through WebGIS. The methods can be applied to some fields, such as person or car supervision and the flow analysis of customers or traffic passengers. Numéro de notice : A2021-883 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi10120803 Date de publication en ligne : 28/11/2021 En ligne : https://doi.org/10.3390/ijgi10120803 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99186 [article]

Analysis on the dynamic deformations of the images from digital film sequences / Tomasz Markowski in Geodesy and cartography, vol 64 n° 1 (June 2015)  

Public [article]  inGeodesy and cartography > vol 64 n° 1 (June 2015) . - pp 43 - 64 Titre : Analysis on the dynamic deformations of the images from digital film sequences Type de document : Article/Communication Auteurs : Tomasz Markowski, Auteur Année de publication : 2015 Article en page(s) : pp 43 - 64 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] caméra vidéo numérique [Termes IGN] chambre non métrique [Termes IGN] déformation d'image [Termes IGN] distorsion d'image [Termes IGN] étalonnage de capteur (imagerie) [Termes IGN] image vidéo [Termes IGN] séquence d'images Résumé : (auteur) Image sequences, in particular digital video sequences, are characterised by the features which result in their high potential as measurement data. However, as early as at the stage of visual assessment of digital film images, originating, in particular, from amateur cameras, occurrence of some deformations may be observed, which may highly influence the results of measurements performed using these images; such deformations differ from deformations occurred in the case of static photographic images. It results both, by the method of image recording, using an electronic shutter and interlaced or progressive scanning, as well as the method of file recording and compression. It is worth to notice the systematic nature of such deformations, which highly depend on mutual motions of a camera and recorded objects. The objective of presented research works was to develop the mathematical description of image deformations, as a function of motion parameters. This would allow for adaptation of the camera calibration process to the demands of sequential imaging, as well as for modification of algorithms of measurements using self-calibration, and, as a result, minimisation of deformations. Another objective was to analyse the influence of deformations, typical for digital film images, on the results of measurements performed using these images, by means of series of experiments, which were based on multiple calibration of static and a moving camera, also with the use of a spatial test field. The first part was made by developing formulas based on some geometric relations, using some simplifications. On the stage of experimental research a certain degree of compatibility of experimental results and theoretical assumptions were confirmed. Numéro de notice : A2015-262 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1515/geocart-2015-0005 En ligne : http://dx.doi.org/10.1515/geocart-2015-0005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76310 [article]

Generation of dense 3D point clouds using a small quadcopter / Julien Li-Chee-Ming in Geomatica, vol 68 n° 4 (December 2014)  

Public [article]  inGeomatica > vol 68 n° 4 (December 2014) . - pp319 - 330 Titre : Generation of dense 3D point clouds using a small quadcopter Type de document : Article/Communication Auteurs : Julien Li-Chee-Ming, Auteur ; Costas Armenakis, Auteur Année de publication : 2014 Article en page(s) : pp319 - 330 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] acquisition de données [Termes IGN] appariement d'images [Termes IGN] caméra vidéo numérique [Termes IGN] compensation par faisceaux [Termes IGN] données localisées 3D [Termes IGN] image aérienne oblique [Termes IGN] image captée par drone [Termes IGN] lasergrammétrie [Termes IGN] lever direct [Termes IGN] lever mobile [Termes IGN] modèle numérique de surface [Termes IGN] semis de points [Termes IGN] visée oblique Résumé : (auteur) La technologie perturbatrice des petits et légers systèmes de véhicules aériens sans pilote (UVS) transforme les applications de géomatique et crée de toutes nouvelles occasions innovatrices de mesurer et modéliser les environnements extérieurs et intérieurs. Les UVS complémentent et, dans certains cas, remplacent les tachéomètres électroniques et les lecteurs laser et fonctionnent comme des systèmes d’arpentage mobiles flexibles. Un petit quadcoptère a été utilisé pour capter des images obliques vidéo à grand recouvrement. Les images vidéo captées par la caméra à bord ont été reconstruites selon une structure incrémentielle à l’aide d’une compensation par faisceaux du mouvement. On a utilisé la correspondance d’images multiples denses pour créer un nuage de points tridimensionnel représentant la surface de la région cartographiée à partir des images vidéo obliques. La position et l’orientation des images étaient aussi estimées en cours de processus. Le modèle de surface numérique dense créé par photogrammétrie a été co-enregistré et comparé à un modèle tridimensionnel existant des bâtiments. Cet article présente la méthodologie utilisée ainsi que les résultats et précisions obtenus. Numéro de notice : A2015-406 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.5623/cig2014-406 En ligne : https://doi.org/10.5623/cig2014-406 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76893 [article]

Exploiting HD camcorders for close-up human movement applications / A. Chong in Photogrammetric record, vol 27 n° 138 (June - August 2012)  

Public [article]  inPhotogrammetric record > vol 27 n° 138 (June - August 2012) . - pp 227 - 237 Titre : Exploiting HD camcorders for close-up human movement applications Type de document : Article/Communication Auteurs : A. Chong, Auteur Année de publication : 2012 Article en page(s) : pp 227 - 237 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie terrestre [Termes IGN] acquisition d'images [Termes IGN] caméra vidéo numérique [Termes IGN] médecine humaine [Termes IGN] santé [Termes IGN] utilisateur Résumé : (Auteur) Lately, the cost of HD video camcorders has decreased greatly and the inclusion of an internal hard disk in many models has eased the bother of downloading video clips from cumbersome tape devices. These factors have increased their potential as 3D recording devices and measurement tools for the health monitoring of patients by practitioners. This investigation determined: (1) the 3D measurement quality of off-the-shelf high definition camcorders for human-movement-related medical applications; (2) the suitability of a low-cost LED synchronisation device for multi-camcorder tracking; and (3) the suitability of these imaging sensors for practitioners. The results show that a four-camcorder system is capable of measuring a 3D distance in a static setting to better than 0·050 mm; it can track a moving calibrated square-wave signal of 0·5 and 1 Hz to better than 0·3 and 0·2 mm, respectively. Using a calibrated scale bar mounted on a moving human leg, the error produced as a result of frame disparity using a low-cost LED frame-synchronising device was under 0·3 mm for a four-, three- and two-camcorder configuration. Numéro de notice : A2012-308 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/j.1477-9730.2012.00673.x Date de publication en ligne : 27/03/2012 En ligne : https://doi.org/10.1111/j.1477-9730.2012.00673.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31754 [article]

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
106-2012021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

An introduction to the technology mobile mapping systems / Gordon Petrie in Geoinformatics, vol 13 n° 1 (01/01/2010)

Public [article]  inGeoinformatics > vol 13 n° 1 (01/01/2010) . - pp 32 - 43 Titre : An introduction to the technology mobile mapping systems Type de document : Article/Communication Auteurs : Gordon Petrie, Auteur Année de publication : 2010 Article en page(s) : pp 32 - 43 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] acquisition d'images [Termes IGN] acquisition de données [Termes IGN] caméra vidéo numérique [Termes IGN] capteur imageur [Termes IGN] GPS-INS [Termes IGN] odomètre [Termes IGN] système de numérisation mobile [Termes IGN] télémètre laser terrestre Résumé : (Auteur) Over the last 20 years, mobile mapping systems have slowly developed, at first mainly in academic research establishments. More recently, a number of commercially operated systems have appeared. These have mostly been one-off systems that have been developed in-house by the companies that are operating them. Most of them have been utilized for the collection of data on road infrastructure or building facades. However, over the last two or three years, some very big companies such as Google, Tele Atlas and NAVTEQ have adopted the technology on a large scale, introducing substantial fleets of mobile mapping vehicles for their imaging and mapping operations. This has resulted in the further rapid development of the technology which can now be regarded as being well established and proven. This article offers an introduction to and survey of the present state-of-the-art of the technology. Copyright GEOinformatics Numéro de notice : A2010-031 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30227 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
262-2010011	SL	Revue	Centre de documentation	Revues en salle	Disponible

Aerial mapping by consumer camcoders / C.A. Rokhmana in GIM international, vol 19 n° 2 (February 2005)

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Potential for calibrating airborne video imagery using preflight calibration coefficients / A. Edirisinghe in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 5 (May 2004)  

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Saisie de la couverture neigeuse de sites avalancheux par des systèmes aéroportés / Julien Vallet (2002)  

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