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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]

Trajectory and image-based detection and identification of UAV / Yicheng Liu in The Visual Computer, vol 37 n° 7 (July 2021)  

Public [article]  inThe Visual Computer > vol 37 n° 7 (July 2021) Titre : Trajectory and image-based detection and identification of UAV Type de document : Article/Communication Auteurs : Yicheng Liu, Auteur ; Luchuan Liao, Auteur ; Hao Wu, Auteur ; et al., Auteur Année de publication : 2021 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] Aves [Termes IGN] caméra de surveillance PTZ [Termes IGN] classification par réseau neuronal convolutif [Termes IGN] détection d'objet [Termes IGN] drone [Termes IGN] forme caractéristique [Termes IGN] interférence [Termes IGN] objet mobile [Termes IGN] reconnaissance de formes [Termes IGN] trajectoire (véhicule non spatial) Résumé : (auteur) Much more attentions have been attracted to the inspection and prevention of unmanned aerial vehicle (UAV) in the wake of increasing high frequency of security accident. Many factors like the interferences and the small fuselage of UAV pose challenges to the timely detection of the UAV. In our work, we present a system that is capable of detecting, recognizing, and tracking an UAV using single camera automatically. For our method, a single pan–tilt–zoom (PTZ) camera detects flying objects and gets their trajectories; then, the trajectory identified as a UAV guides the camera and PTZ to capture the detailed region image of the target. Therefore, the images can be classified into the UAV and interference classes (such as birds) by the convolution neural network classifier trained with our image dataset. For the target recognized as a UAV with the double verification, the radio jammer emits the interferential radio to disturb its control radio and GPS. This system could be applied in some complex environment where many birds and UAV appear simultaneously. Numéro de notice : A2021-541 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s00371-020-01937-y Date de publication en ligne : 29/07/2020 En ligne : https://doi.org/10.1007/s00371-020-01937-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98020 [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]

Accuracy analysis of a dual camera system with an asymmetric photogrammetric configuration / Bo Wu in Photogrammetric Engineering & Remote Sensing, PERS, vol 81 n° 3 (March 2015)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 81 n° 3 (March 2015) . - pp 219 - 228 Titre : Accuracy analysis of a dual camera system with an asymmetric photogrammetric configuration Type de document : Article/Communication Auteurs : Bo Wu, Auteur ; Lei Ye, Auteur ; Yuansheng Yang, Auteur Année de publication : 2015 Article en page(s) : pp 219 - 228 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] caméra de surveillance PTZ [Termes IGN] caméra numérique [Termes IGN] image multi sources [Termes IGN] modèle géométrique de prise de vue [Termes IGN] objectif grand angulaire [Termes IGN] précision des mesures Résumé : (auteur) This paper presents a dual camera system combining a wide field-of-view (FOV) surveillance camera and a pan-tiltzoom (PTZ) camera with an asymmetric photogrammetric configuration, and focuses on the analysis of its attainable measurement accuracy. First, we discuss the geometric modeling of the asymmetric photogrammetric configuration and analyze the accuracy of measurement based on error propagation for different baseline lengths, different focal lengths, and different pan angles of the PTZ camera. Second, we performed a comprehensive accuracy analysis based on Monte Carlo simulation, which incorporated artificial noise into the input data. Third, we conducted actual experiments in indoor and outdoor environments to verify the theoretical and simulation results. We found that the baseline length between the dual cameras was the main factor influencing measurement accuracy. Increase of the PTZ camera focal length could improve the measurement accuracy, but this trend was not significant when its focal length was relatively long. The pan angle of the PTZ camera also influenced the measurement accuracy, but this influence was not significant at short ranges. From these discoveries, we present an optimum configuration of the dual camera system for better than 1 percent measurement accuracy of the range within a normal observation range (e.g., 60 m). This proposed dual camera system provides enhanced machine vision capabilities that can be used in various applications. Numéro de notice : A2015-971 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.81.3.219-228 En ligne : http://dx.doi.org/10.14358/PERS.81.3.219-228 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80029 [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)  

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Indoor positioning technologies / R. Mautz (2012)    

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Le plus beau des périples / Jean-Marie Séïté in Géomatique expert, n° 78 (01/01/2011)

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GIS-augmented video surveillance / A. Milosavljevic in International journal of geographical information science IJGIS, vol 24 n° 9 (september 2010)  

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

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Comparative geometric and radiometric evaluation of mobile phone and still video cameras / Devrim Akca in Photogrammetric record, vol 24 n° 127 (September - November 2009)  

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An inexpensive stereo-image capture tool for motion study / A.K. Chong in Photogrammetric record, vol 22 n° 119 (September - November 2007)  

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Lidar on the level in Afghanistan: GPS, inertial map the Kabul road / S. Newby in GPS world, vol 16 n° 7 (July 2005)

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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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