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Noise reduction of hyperspectral imagery using hybrid spatial-spectral derivative-domain wavelet shrinkage / H. Othman in IEEE Transactions on geoscience and remote sensing, vol 44 n° 2 (February 2006)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 44 n° 2 (February 2006) . - pp 397 - 408 Titre : Noise reduction of hyperspectral imagery using hybrid spatial-spectral derivative-domain wavelet shrinkage Type de document : Article/Communication Auteurs : H. Othman, Auteur ; S.E. Qian, Auteur Année de publication : 2006 Article en page(s) : pp 397 - 408 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] classification hypercube [Termes IGN] filtrage du bruit [Termes IGN] image AVIRIS [Termes IGN] image hyperspectrale [Termes IGN] ondelette [Termes IGN] seuillage d'image Résumé : (Auteur) In this paper, a new noise reduction algorithm is introduced and applied to the problem of denoising hyperspectral imagery. This algorithm resorts to the spectral derivative domain, where the noise level is elevated, and benefits from the dissimilarity of the signal regularity in the spatial and the spectral dimensions of hyperspectral images. The performance of the new algorithm is tested on two different hyperspectral datacubes : an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) datacube that is acquired in a vegetation-dominated site and a simulated AVIRIS datacube that simulates a geological site. The new algorithm provides signal-to-noise-ratio improvement up to 84.44% and 98.35% in the first and the second datacubes, respectively. Numéro de notice : A2006-125 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2005.860982 En ligne : https://doi.org/10.1109/TGRS.2005.860982 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27852 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-06021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Contextual reconstruction of cloud-contaminated multitemporal multispectral image / F. Melgani in IEEE Transactions on geoscience and remote sensing, vol 44 n° 2 (February 2006)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 44 n° 2 (February 2006) . - pp 442 - 455 Titre : Contextual reconstruction of cloud-contaminated multitemporal multispectral image Type de document : Article/Communication Auteurs : F. Melgani, Auteur Année de publication : 2006 Article en page(s) : pp 442 - 455 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse comparative [Termes IGN] classification non dirigée [Termes IGN] filtrage du rayonnement [Termes IGN] image Landsat-ETM+ [Termes IGN] image multibande [Termes IGN] image multitemporelle [Termes IGN] nébulosité [Termes IGN] prévision linéaire [Termes IGN] prévision non-linéaire [Termes IGN] prise en compte du contexte [Termes IGN] reconstruction d'image Résumé : (Auteur) The frequent presence of clouds in passive remotely sensed imagery severely limits its regular exploitation in various application fields. Thus, the removal of cloud cover from this imagery represents an important preprocessing task consisting in the reconstruction of cloud-contaminated data. The intent of this study is to propose two novel general methods for the reconstruction of areas obscured by clouds in a sequence of multitemporal multispectral images. Given a cloud-contaminated image of the sequence, each area of missing measurements is reconstructed through an unsupervised contextual prediction process that reproduces the local spectro-temporal relationships between the considered image and an opportunely selected subset of the remaining temporal images. In the first method, the contextual prediction process is implemented by means of an ensemble of linear predictors, each trained over a local multitemporal region that is spectrally homogeneous in each temporal image of the selected subset. In order to obtain such regions, each temporal image is locally classified by an unsupervised classifier based on the expectation-maximization (EM) algorithm. In the second method, the local spectro-temporal relationships are reproduced by a single nonlinear predictor based on the support vector machines (SVM) approach. To illustrate the performance of the two proposed methods, an experimental analysis on a sequence of three temporal images acquired by the Landsat-7 Enhanced Thematic Mapper Plus sensor over a total period of four months is reported and discussed. It includes a detailed simulation study that aims at assessing with different reconstruction quality criteria the accuracy of the methods in different qualitative and quantitative cloud contamination conditions. Compared with two techniques based on compositing algorithms for cloud removal, the proposed methods show a clear superiority, which makes them a promising and useful tool in solving the considered problem, whose great complexity is commensurate with its practical importance. Numéro de notice : A2006-126 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2005.861929 En ligne : https://doi.org/10.1109/TGRS.2005.861929 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27853 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-06021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Spatiotriangulation with multisensor HR stereo-images / Thierry Toutin in IEEE Transactions on geoscience and remote sensing, vol 44 n° 2 (February 2006)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 44 n° 2 (February 2006) . - pp 456 - 462 Titre : Spatiotriangulation with multisensor HR stereo-images Type de document : Article/Communication Auteurs : Thierry Toutin , Auteur Année de publication : 2006 Article en page(s) : pp 456 - 462 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie spatiale [Termes IGN] compensation par faisceaux [Termes IGN] compensation par moindres carrés [Termes IGN] données multicapteurs [Termes IGN] erreur moyenne quadratique [Termes IGN] géoréférencement [Termes IGN] image Ikonos [Termes IGN] image Quickbird [Termes IGN] image SPOT-HRG [Termes IGN] image SPOT-HRS [Termes IGN] modèle stéréoscopique [Termes IGN] point de vérification [Termes IGN] points homologues [Termes IGN] précision géométrique (imagerie) [Termes IGN] spatiotriangulation Résumé : (Auteur) The objective of this research study was to evaluate the spatiotriangulation applied to multiltisensor high-resolution satellite stereo-images, which enabled the simultaneous geometric processing of a large number of stereo-pairs together to reduce the control point requirement. The spatiotriangulation is based on the three-dimensional physical models developed for multisensor images at the Canada Centre for Remote Sensing, Natural Resources Canada and on a least squares block stereo-bundle adjustment process with orbital constraints. The spatiotriangulation was applied to five along-/across-track stereo-images [panchromatic Systeme Pour l'Observation de la Terre 5 (SPOT-5) High-Resolution-Stereoscopy (HRS) and High-Resolution-Geometry (HRG), Ikonos, and QuickBird] acquired over Quebec, Canada. The first results of stereo/block bundle adjustment showed that the same error residuals than the input data errors (1/2 to 1-2 pixels) were obtained depending of the stereo-images, whether independently or simultaneously processed. The second and most important results were related to simultaneous stereo-bundle adjustments of the largest "master" SPOT-5 stereo-pair (either HRS or HRG) using 12 ground control points (GCPs) and the smallest "slave" stereo-pair(s) using no GCP but only stereo tie-points (TPs). Better results were normally obtained with SPOT-5-HRG (5-m resolution) as the "master" stereo-pair due to less difference in the sensors resolution than with SPOT-5 HRS. The root mean square errors, verified by independent check points (ICPs) belonging only to the "slave" stereo-pairs, were around 2 in in the three axes. However, the combined image pointing and map errors of ICPs (1-2 m) are included in these 2-m error results, and the internal accuracy of the stereo-pairs should thus be better (less than one resolution). The research study demonstrated thus the possibility to use the largest stereo-pair with a reduced number of GCPs to simultaneously adjust single or multiple stereo-pair(s) with only stereo TPs, and with no degradation in the accuracy. Numéro de notice : A2006-127 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2005.861005 En ligne : https://doi.org/10.1109/TGRS.2005.861005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27854 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-06021	RAB	Revue	Centre de documentation	En réserve L003	Disponible