Descripteur
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externesEtendre la recherche sur niveau(x) vers le bas
Camera orientation, calibration and inverse perspective with uncertainties: a Bayesian method applied to area estimation from diverse photographs / Grégoire Guillet in ISPRS Journal of photogrammetry and remote sensing, vol 159 (January 2020)
Titre : Camera orientation, calibration and inverse perspective with uncertainties: a Bayesian method applied to area estimation from diverse photographs Type de document : Article/Communication Auteurs : Grégoire Guillet, Auteur ; Thomas Guillet, Auteur ; Ludovic Ravanel, Auteur Année de publication : 2020 Article en page(s) : pp 237 - 255 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes descripteurs IGN] ajustement de paramètres
[Termes descripteurs IGN] appariement d'images
[Termes descripteurs IGN] autocorrélation spatiale
[Termes descripteurs IGN] distorsion d'image
[Termes descripteurs IGN] estimation bayesienne
[Termes descripteurs IGN] étalonnage de chambre métrique
[Termes descripteurs IGN] figuration de la densité
[Termes descripteurs IGN] fonction inverse
[Termes descripteurs IGN] image 2D
[Termes descripteurs IGN] image aérienne
[Termes descripteurs IGN] incertitude géométrique
[Termes descripteurs IGN] longueur focale
[Termes descripteurs IGN] méthode de Monte-Carlo par chaînes de Markov
[Termes descripteurs IGN] modèle numérique de surface
[Termes descripteurs IGN] orientation externe
[Termes descripteurs IGN] photographie numérique
[Termes descripteurs IGN] vue 3D
[Termes descripteurs IGN] vue perspectiveRésumé : (Auteur) Large collections of images have become readily available through modern digital catalogs, from sources as diverse as historical photographs, aerial surveys, or user-contributed pictures. Exploiting the quantitative information present in such wide-ranging collections can greatly benefit studies that follow the evolution of landscape features over decades, such as measuring areas of glaciers to study their shrinking under climate change. However, many available images were taken with low-quality lenses and unknown camera parameters. Useful quantitative data may still be extracted, but it becomes important to both account for imperfect optics, and estimate the uncertainty of the derived quantities. In this paper, we present a method to address both these goals, and apply it to the estimation of the area of a landscape feature traced as a polygon on the image of interest. The technique is based on a Bayesian formulation of the camera calibration problem. First, the probability density function (PDF) of the unknown camera parameters is determined for the image, based on matches between 2D (image) and 3D (world) points together with any available prior information. In a second step, the posterior distribution of the feature area of interest is derived from the PDF of camera parameters. In this step, we also model systematic errors arising in the polygon tracing process, as well as uncertainties in the digital elevation model. The resulting area PDF therefore accounts for most sources of uncertainty. We present validation experiments, and show that the model produces accurate and consistent results. We also demonstrate that in some cases, accounting for optical lens distortions is crucial for accurate area determination with consumer-grade lenses. The technique can be applied to many other types of quantitative features to be extracted from photographs when careful error estimation is important. Numéro de notice : A2020-015 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.11.013 date de publication en ligne : 02/12/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.11.013 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94404
in ISPRS Journal of photogrammetry and remote sensing > vol 159 (January 2020) . - pp 237 - 255[article]Réservation
Réserver ce documentExemplaires (3)
Code-barres Cote Support Localisation Section Disponibilité 081-2020011 SL Revue Centre de documentation Revues en salle Disponible 081-2020013 DEP-RECP Revue MATIS Dépôt en unité Exclu du prêt 081-2020012 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt
Titre : BIM-Tracker: A model-based visual tracking approach for indoor localisation using a 3D building model Type de document : Article/Communication Auteurs : Debaditya Acharya, Auteur ; Milad Ramezani, Auteur ; Kourosh Khoshelham, Auteur ; Stephan Winter, Auteur Année de publication : 2019 Article en page(s) : pp 157 - 171 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes descripteurs IGN] algorithme de Gauss-Newton
[Termes descripteurs IGN] appariement de données localisées
[Termes descripteurs IGN] corrélation à l'aide de traits caractéristiques
[Termes descripteurs IGN] estimation de pose
[Termes descripteurs IGN] filtre de Kalman
[Termes descripteurs IGN] longueur focale
[Termes descripteurs IGN] Matlab
[Termes descripteurs IGN] méthode des moindres carrés
[Termes descripteurs IGN] modèle 3D du site
[Termes descripteurs IGN] positionnement en intérieur
[Termes descripteurs IGN] trajectoireRésumé : (Auteur) This article presents an accurate and robust visual indoor localisation approach that not only is infrastructure-free, but also avoids accumulation error by taking advantage of (1) the widespread ubiquity of mobile devices with cameras and (2) the availability of 3D building models for most modern buildings. Localisation is performed by matching image sequences captured by a camera, with a 3D model of the building in a model-based visual tracking framework. Comprehensive evaluation of the approach with a photo-realistic synthetic dataset shows the robustness of the localisation approach under challenging conditions. Additionally, the approach is tested and evaluated on real data captured by a smartphone. The results of the experiments indicate that a localisation accuracy better than 10 cm can be achieved by using this approach. Since localisation errors do not accumulate the proposed approach is suitable for indoor localisation tasks for long periods of time and augmented reality applications, without requiring any local infrastructure. A MATLAB implementation can be found on https://github.com/debaditya-unimelb/BIM-Tracker. Numéro de notice : A2019-139 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.02.014 date de publication en ligne : 27/02/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.02.014 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92473
in ISPRS Journal of photogrammetry and remote sensing > vol 150 (April 2019) . - pp 157 - 171[article]Réservation
Réserver ce documentExemplaires (3)
Code-barres Cote Support Localisation Section Disponibilité 081-2019041 SL Revue Centre de documentation Revues en salle Disponible 081-2019043 DEP-RECP Revue MATIS Dépôt en unité Exclu du prêt 081-2019042 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt
Titre : Efficiently annotating object images with absolute size information using mobile devices Type de document : Article/Communication Auteurs : Martin Hofmann, Auteur ; Marco Seeland, Auteur ; Patrick Mäder, Auteur Année de publication : 2019 Article en page(s) : pp 207 - 224 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes descripteurs IGN] appareil portable
[Termes descripteurs IGN] appariement automatique
[Termes descripteurs IGN] image numérique
[Termes descripteurs IGN] longueur focaleRésumé : (Auteur) The projection of a real world scenery to a planar image sensor inherits the loss of information about the 3D structure as well as the absolute dimensions of the scene. For image analysis and object classification tasks, however, absolute size information can make results more accurate. Today, the creation of size annotated image datasets is effort intensive and typically requires measurement equipment not available to public image contributors. In this paper, we propose an effective annotation method that utilizes the camera within smart mobile devices to capture the missing size information along with the image. The approach builds on the fact that with a camera, calibrated to a specific object distance, lengths can be measured in the object’s plane. We use the camera’s minimum focus distance as calibration distance and propose an adaptive feature matching process for precise computation of the scale change between two images facilitating measurements on larger object distances. Eventually, the measured object is segmented and its size information is annotated for later analysis. A user study showed that humans are able to retrieve the calibration distance with a low variance. The proposed approach facilitates a measurement accuracy comparable to manual measurement with a ruler and outperforms state-of-the-art methods in terms of accuracy and repeatability. Consequently, the proposed method allows in-situ size annotation of objects in images without the need for additional equipment or an artificial reference object in the scene. Numéro de notice : A2018-600 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s11263-018-1093-3 date de publication en ligne : 24/05/2018 En ligne : https://doi.org/10.1007/s11263-018-1093-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92527
in International journal of computer vision > vol 127 n° 2 (February 2019) . - pp 207 - 224[article]
Titre : Automatic camera calibration in close range photogrammetry Type de document : Article/Communication Auteurs : Clive Simpson Fraser, Auteur Année de publication : 2013 Article en page(s) : pp 381 - 388 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes descripteurs IGN] aberration chromatique
[Termes descripteurs IGN] autoétalonnage
[Termes descripteurs IGN] chambre de prise de vue numérique
[Termes descripteurs IGN] chambre métrique
[Termes descripteurs IGN] espace objet
[Termes descripteurs IGN] étalonnage de chambre métrique
[Termes descripteurs IGN] longueur focale
[Termes descripteurs IGN] orientation interne
[Termes descripteurs IGN] photogrammétrie métrologiqueRésumé : (Auteur) Automatic camera calibration using self-calibration with the aid of coded targets is now very much the norm in close-range photogrammetry. This is irrespective of whether the cameras to be calibrated are high-end metric, or the digital SLRs and consumer-grade models that are increasingly being employed for image-based 3D measurement. Automation has greatly simplified the calibration task, but there are real prospects that important camera calibration issues may be overlooked in what has become an almost black-box operation. This paper discusses the impact of a number of such issues, some of which relate to the functional model adopted for self-calibration, and others to practical aspects which need to be taken into account when pursuing optimal calibration accuracy and integrity. Issues discussed include interior orientation stability, calibration reliability, focal plane distortion, image point distribution, variation in lens distortion with image scale, color imagery and chromatic aberration, and whether 3D object space control is warranted. By appreciating and accounting for these issues, users of automatic camera calibration will enhance the prospect of achieving an optimal recovery of scene-independent camera calibration parameters. Numéro de notice : A2013-207 Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.79.4.381 En ligne : https://doi.org/10.14358/PERS.79.4.381 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32345
in Photogrammetric Engineering & Remote Sensing, PERS > vol 79 n° 4 (April 2013) . - pp 381 - 388[article]Réservation
Réserver ce documentExemplaires (2)
Code-barres Cote Support Localisation Section Disponibilité 105-2013041 RAB Revue Centre de documentation En réserve 3L Disponible 105-2013042 RAB Revue Centre de documentation En réserve 3L Disponible
Titre : A large format camera for national mapping purposes Type de document : Article/Communication Auteurs : Jean Philippe Souchon, Auteur ; Christian Thom Année de publication : 2012 Article en page(s) : pp 48 - 53 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes descripteurs IGN] chambre de prise de vue numérique
[Termes descripteurs IGN] colorimétrie
[Termes descripteurs IGN] géoréférencement direct
[Termes descripteurs IGN] longueur focale
[Termes descripteurs IGN] système de prise de vue modulaireRésumé : (Auteur) IGN CAMv2 project started in 2006 and is composed of two main steps. At first, a four-channel medium format camera system was developed. The basic element of this new system is a camera head built around the Kodak KAF-39 000, 39 mega-pixel array sensor (7,216 x 5,412 pixels). Three systems in this medium format colour configuration, with four nadir-viewing camera heads (RGB and Near-lnfrared-NIR), operated for IGN national orthophotography production, during the summer 2009. Thanks to the versatile and modular aspect of the new camera system, the second step of our project was reachable: gathering eight camera heads on the same gyro-stabilised mount in order to achieve 155 megapixels pan-sharpened images with a pan-sharpening ratio of 2 x 2, and a final swath width of about 14,400 pixels. This large format configuration has been designed with two combinations of focal lengths. A 45-90 mm version allows 3D city models acquisition, and a 60-120 mm version for orthophotography acquisition. Good realistic colorimetric quality is obtained with this camera system thanks to specially designed colour filters. This system can be linked to a FMS/INS in order to obtain a direct geo-referencing of images, and the user friendliness for the operators of a state-of-the-art flight management software. Numéro de notice : A2012-567 Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32013
in Revue Française de Photogrammétrie et de Télédétection > n° 200 (Novembre 2012) . - pp 48 - 53[article]Réservation
Réserver ce documentExemplaires (2)
Code-barres Cote Support Localisation Section Disponibilité 018-2012051 RAB Revue Centre de documentation En réserve 3L Disponible 018-2012052 RAB Revue Centre de documentation En réserve 3L Disponible PermalinkPermalinkCalibration du photothéodolite de l'IGN et traitements d'images pour la surveillance d'ouvrages au sein de l'unité des travaux spéciaux / S. Doz (2005)
PermalinkPermalinkPermalinkPermalinkPermalinkPermalinkPermalinkPermalink
