Détail de l'auteur
Auteur Grégoire Mercier |
Documents disponibles écrits par cet auteur (17)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Unmixing polarimetric radar images based on land cover type identified by higher resolution optical data before target decomposition: application to forest and bare soil / Sébastien Giordano in IEEE Transactions on geoscience and remote sensing, vol 56 n° 10 (October 2018)
[article]
Titre : Unmixing polarimetric radar images based on land cover type identified by higher resolution optical data before target decomposition: application to forest and bare soil Type de document : Article/Communication Auteurs : Sébastien Giordano , Auteur ; Grégoire Mercier, Auteur ; Jean-Paul Rudant , Auteur Année de publication : 2018 Projets : 1-Pas de projet / Article en page(s) : pp 5850 - 5862 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse des mélanges spectraux
[Termes IGN] analyse linéaire des mélanges spectraux
[Termes IGN] biomasse aérienne
[Termes IGN] décomposition spectrale
[Termes IGN] données polarimétriques
[Termes IGN] forêt
[Termes IGN] image Radarsat
[Termes IGN] matrice de covariance
[Termes IGN] occupation du sol
[Termes IGN] polarimétrie radar
[Termes IGN] sol nu
[Termes IGN] surface forestièreRésumé : (auteur) Extracting information from a polarimetric radar representation usually consists in decomposing it with target decomposition algorithms. This first step can be seen as a geometric analysis of the polarimetric information: the identification of physical radar scattering mechanisms. The problem is that average physical parameters are estimated. As a consequence, these parameters might not describe correctly any of the land cover types that can be mixed together into the radar resolution cell. Therefore, using the polarimetric parameters for land cover classification is challenging. The novelty of the method is to propose a thematic analysis of the polarimetric information preceding the geometric one. The objective is to assess if splitting off polarimetric information on a land cover type basis before applying usual target decomposition algorithms can produce more consistent radar scattering mechanisms when land cover classes are mixed inside the radar resolution cell. A cooperative fusion framework in which very high-resolution optical images are used to unmix physical radar scattering mechanisms is proposed. For bare soil and forests, we point out that a linear unmixing model applied to the covariance matrix is able to split off polarimetric information on a land cover type basis. The assessment of the unmixed radar matrices is carried out with polarimetric radar images from the Radarsat-2 satellite. It was found that despite speckle, the reconstructed radar information after the unmixing process is statistically relevant with the observations. The question whether the unmixed radar images contain relevant thematic information is more challenging, but results tend to validate this property. This method could be used to have a better estimation of vegetation biomass in the context of open forested areas. Numéro de notice : A2018-331 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2018.2827258 Date de publication en ligne : 09/07/2018 En ligne : https://doi.org/10.1109/TGRS.2018.2827258 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90475
in IEEE Transactions on geoscience and remote sensing > vol 56 n° 10 (October 2018) . - pp 5850 - 5862[article]Geometric multi-wavelet total variation for SAR image time series analysis / Abdourrahmane M. Atto (2018)
Titre : Geometric multi-wavelet total variation for SAR image time series analysis Type de document : Article/Communication Auteurs : Abdourrahmane M. Atto, Auteur ; Anoumou Kemavo, Auteur ; Jean-Paul Rudant , Auteur ; Grégoire Mercier, Auteur Editeur : Chambéry : Université de Savoie Année de publication : 2018 Conférence : FUSION 2018, 21th International Conference on Information Fusion 10/07/2018 13/07/2018 Cambridge Royaume-Uni Proceedings IEEE Projets : PHOENIX / Atto, Abdourrahmane M. Importance : pp Note générale : bibliographie
Projet PHOENIX ANR-15-CE23-00Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] Amazonie
[Termes IGN] forêt tropicale
[Termes IGN] image radar moirée
[Termes IGN] image Sentinel-SAR
[Termes IGN] Oyapoc (fleuve)
[Termes IGN] série temporelleRésumé : (auteur) A time series issued from modern synthetic aperture radar satellite imaging sensors is a huge dataset composed by many hundreds of million pixels when observing large-scale earth structures such as big forests or glaciers. A concise monitoring of these large scale structures for anomaly spotting thus requires loading and analyzing huge spatio/polarimetric multi-temporal image series. The contributions of the present paper for the sake of parsimonious analysis of such huge datasets are associated with a framework having two main processing stages. The first stage is the derivation of an index called geometric multi-wavelet total variation for fast and robust anomaly spotting. This index is useful for identifying significant abnormal patterns appearing as geo-spatial non-stationarities in multi-wavelet total variation map. The second stage consists in the proposal of a concise asymmetric multi-date change information matrix on regions associated with significant multi-wavelet total variations. This stage is necessary for a fine characterization of change impacts on existing geo-spatial structures. Experimental tests based on Sentinel-1 data show relevant results on a wide Amazonian forest surrounding the Franco-Brazilian Oyapock Bridge. Numéro de notice : C2018-125 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.23919/ICIF.2018.8455223 Date de publication en ligne : 06/09/2018 En ligne : https://doi.org/10.23919/ICIF.2018.8455223 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100016 Mapping and characterization of hydrological dynamics in coastal marsh using high temporal resolution Sentinel-1 images / Cécile Cazals in Remote sensing, vol 8 n° 7 (July 2016)
[article]
Titre : Mapping and characterization of hydrological dynamics in coastal marsh using high temporal resolution Sentinel-1 images Type de document : Article/Communication Auteurs : Cécile Cazals , Auteur ; Sébastien Rapinel, Auteur ; Pierre-Louis Frison , Auteur ; Anne Bonis, Auteur ; Grégoire Mercier, Auteur ; Clément Mallet , Auteur ; Samuel Corgne, Auteur ; Jean-Paul Rudant , Auteur Année de publication : 2016 Article en page(s) : pp 1 - 17 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse diachronique
[Termes IGN] classification
[Termes IGN] données hydrographiques
[Termes IGN] gestion de l'eau
[Termes IGN] image radar moirée
[Termes IGN] image Sentinel-SAR
[Termes IGN] inondation
[Termes IGN] marais poitevin
[Termes IGN] polarimétrie radar
[Termes IGN] seuillage d'imageRésumé : (Auteur) In Europe, water levels in wetlands are widely controlled by environmental managers and farmers. However, the influence of these management practices on hydrodynamics and biodiversity remains poorly understood. This study assesses advantages of using radar data from the recently launched Sentinel-1A satellite to monitor hydrological dynamics of the Poitevin marshland in western France. We analyze a time series of 14 radar images acquired in VV and HV polarizations from December 2014 to May 2015 with a 12-day time step. Both polarizations are used with a hysteresis thresholding algorithm which uses both spatial and temporal information to distinguish open water, flooded vegetation and non-flooded grassland. Classification results are compared to in situ piezometric measurements combined with a Digital Terrain Model derived from LiDAR data. Results reveal that open water is successfully detected, whereas flooded grasslands with emergent vegetation and fine-grained patterns are detected with moderate accuracy. Five hydrological regimes are derived from the flood duration and mapped. Analysis of time steps in the time series shows that decreased temporal repetitivity induces significant differences in estimates of flood duration. These results illustrate the great potential to monitor variations in seasonal floods with the high temporal frequency of Sentinel-1A acquisitions. Numéro de notice : A2016--108 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs8070570 Date de publication en ligne : 05/07/2016 En ligne : http://dx.doi.org/10.3390/rs8070570 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84725
in Remote sensing > vol 8 n° 7 (July 2016) . - pp 1 - 17[article]Documents numériques
en open access
A2016--108_Mapping_and_characterization.pdfAdobe Acrobat PDF Change detection between SAR images using a pointwise approach and graph theory / Minh-Tan Pham in IEEE Transactions on geoscience and remote sensing, vol 54 n° 4 (April 2016)
[article]
Titre : Change detection between SAR images using a pointwise approach and graph theory Type de document : Article/Communication Auteurs : Minh-Tan Pham, Auteur ; Grégoire Mercier, Auteur ; Julien Michel, Auteur Année de publication : 2016 Article en page(s) : pp 2020 - 2032 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] bruit rose
[Termes IGN] classification pixellaire
[Termes IGN] détection de changement
[Termes IGN] graphe
[Termes IGN] image radar
[Termes IGN] image radar moirée
[Termes IGN] relation topologique
[Termes IGN] traitement du signal
[Termes IGN] voisinage (relation topologique)Résumé : (Auteur) This paper investigates the problem of change detection in multitemporal synthetic aperture radar (SAR) images. Our motivation is to avoid using a large-size dense neighborhood around each pixel to measure its change level, which is usually considered by classical methods in order to perform their accurate detectors. Therefore, we propose to develop a pointwise approach to detect land-cover changes between two SAR images employing the principle of signal processing on graphs. First, a set of characteristic points is extracted from one of the two images to capture the image's significant contextual information. A weighted graph is then constructed to encode the interaction among these keypoints and hence capture the local geometric structure of this first image. With regard to this graph, the coherence of the information carried by the two images is considered for measuring changes between them. In other words, the change level will depend on how much the second image still conforms to the graph structure constructed from the first image. Additionally, due to the presence of speckle noise in SAR imaging, the log-ratio operator will be exploited to perform the image comparison measure. Experimental results performed on real SAR images show the effectiveness of the proposed algorithm, in terms of detection performance and computational complexity, compared to classical methods. Numéro de notice : A2016-838 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2493730 En ligne : http://dx.doi.org/10.1109/TGRS.2015.2493730 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82882
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 4 (April 2016) . - pp 2020 - 2032[article]Pointwise approach for texture analysis and characterization from very high resolution remote sensing images / Minh-Tan Pham (2016)
Titre : Pointwise approach for texture analysis and characterization from very high resolution remote sensing images Type de document : Thèse/HDR Auteurs : Minh-Tan Pham, Auteur ; Grégoire Mercier, Directeur de thèse Editeur : Université Bretagne Loire Année de publication : 2016 Importance : 177 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse pour obtenir le grade de Docteur de Telecom Bretagne, Mention : Sciences et Technologies de l'Information et de la Communication, en Informatique Traitement des imagesLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] classification
[Termes IGN] classification pixellaire
[Termes IGN] covariance
[Termes IGN] détection de changement
[Termes IGN] image à très haute résolution
[Termes IGN] image optique
[Termes IGN] image radar
[Termes IGN] matrice de covariance
[Termes IGN] segmentation d'image
[Termes IGN] texture d'image
[Termes IGN] théorie des graphes
[Termes IGN] viticultureIndex. décimale : THESE Thèses et HDR Résumé : (auteur) This thesis work proposes a novel pointwise approach for texture analysis in the scope of very high resolution (VHR) remote sensing imagery. This approach takes into consideration only characteristic pixels, not all pixels of the image, to represent and characterize textural features. Due to the fact that increasing the spatial resolution of satellite sensors leads to the lack of stationarity hypothesis in the acquired images, such an approach becomes relevant since only the interaction and characteristics of keypoints are exploited. Moreover, as this technique does not need to consider all pixels inside the image like classical dense approaches, it is more capable to deal with large-size image data offered by VHR remote sensing acquisition systems. In this work, our pointwise strategy is performed by exploiting the local maximum and local minimum pixels (in terms of intensity) extracted from the image. It is integrated into several texture analysis frameworks with the help of different techniques and methods such as the graph theory, the covariance-based approach, the geometric distance measurement, etc. As a result, a variety of texture-based applications using remote sensing data (both VHR optical and radar images) are tackled such as image retrieval, segmentation, classification, and change detection, etc. By performing dedicated experiments to each thematic application, the effectiveness and relevance of the proposed approach are confirmed and validated. Note de contenu : I- Introduction
II- Pointwise approach with graph theory
III- Pointwise approach with structural features
IV ConclusionNuméro de notice : 25815 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Informatique Traitement des images : Telecom Bretagne : 2016 nature-HAL : Thèse DOI : sans En ligne : https://tel.archives-ouvertes.fr/tel-01464333v2 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95080 Editorial Theme Issue "Multitemporal remote sensing data analysis" / Clément Mallet in ISPRS Journal of photogrammetry and remote sensing, vol 107 (September 2015)Permalinkvol 107 - September 2015 - Multitemporal remote sensing data analysis (Bulletin de ISPRS Journal of photogrammetry and remote sensing) / Clément MalletPermalinkAssessment of the relevance of information derived from the unmixing of polarimetric radar images / Sébastien Giordano (2015)PermalinkContribution of textural information from TerraSAR-X image for forest mapping / Cécile Cazals (2015)PermalinkDémélange d’images radar polarimétrique par séparation thématique de sources / Sébastien Giordano (2015)PermalinkUnmixing polarimetric radar images based on land cover type before target decomposition / Sébastien Giordano (2014)PermalinkMissing-area reconstruction in multispectral images under a compressive sensing perspective / Luca Lorenzi in IEEE Transactions on geoscience and remote sensing, vol 51 n° 7 Tome 1 (July 2013)PermalinkA complete processing chain for shadow detection and reconstruction in VHR images / L. Lorenzi in IEEE Transactions on geoscience and remote sensing, vol 50 n° 9 (October 2012)PermalinkA proposed framework to unmix scattering mechanisms of polarimetric radar images using very high resolution optical images / Sébastien Giordano in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-7 (2012)PermalinkApproches de classification évidentielle et paradoxale d'images satellitaires multispectrales pour l'amélioration de la carte d'occupation du sol : application au milieu urbain et périurbain de la région d'Alger / R. Khedam in Revue Française de Photogrammétrie et de Télédétection, n° 190 (Septembre 2008)Permalink