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A spectral and spatial source separation of multispectral images / M.A. Loghmari in IEEE Transactions on geoscience and remote sensing, vol 44 n° 12 (December 2006)
[article]
Titre : A spectral and spatial source separation of multispectral images Type de document : Article/Communication Auteurs : M.A. Loghmari, Auteur ; Mohamed Saber Naceur, Auteur ; Mohamed-Rached Boussema, Auteur Année de publication : 2006 Article en page(s) : pp 3659 - 3673 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] classification bayesienne
[Termes IGN] données multisources
[Termes IGN] hétérogénéité
[Termes IGN] image multibande
[Termes IGN] occupation du sol
[Termes IGN] segmentation d'image
[Termes IGN] séparabilité
[Termes IGN] signature spectraleRésumé : (Auteur) This paper deals with the problem of blind source separation of remote sensing data based on a Bayesian estimation framework. We consider the case of multispectral images in which we have observed images of the same zone through different spectral bands. The land cover types existing in the scanned zone constitute the sources to separate. Associating each source to a specific significant theme remains the real challenge in the source-separation method applied to satellite images. In fact, multispectral images consist of multiple channels, each channel containing data acquired from different bands within the frequency spectrum. Since most objects emit or reflect energy over a large spectral bandwidth, there usually exists a significant correlation between channels. This constitutes the first difficulty for sources identification. The second difficulty lies in the heterogeneity of most of the geological and vegetative ground surfaces. In this case, the geometrical projection of a single detector element at the Earth's surface, which is sometimes called the instantaneous field of view, is formed from a mixture of spectral signatures. In such circumstances, the needed information is either not available or not reliable. In this paper, the goal is to establish a new approach based on a two-level source separation (TLSS), which consists of a spectral separation along the different used bands and a spatial separation along neighboring pixels of each image band. The spectral separation has been used prior to the Bayesian approach, and it is based on a second-order statistics approach that exploits the correlation through different spectral bands of the multispectral sensor. The given images are represented according to independent axes that provide more effective representation of the information within the observation images. The spectral separation consists of identifying the sources without resorting to any a priori information, hence the term blind. The obtained source-separation represent the starting point for the Bayesian approach, which is known for its weakness in front of initial conditions. To identify a significant theme for each source, we have to spatially separate each image based on a Bayesian source-separation framework. The proposed approach has the added advantages of the blind source method as well as the Bayesian method. It should give segmented images related to each theme covering the scanned zone, which are the TLSS results of the observation images. Copyright IEEE Numéro de notice : A2006-559 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2006.882261 En ligne : https://doi.org/10.1109/TGRS.2006.882261 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28282
in IEEE Transactions on geoscience and remote sensing > vol 44 n° 12 (December 2006) . - pp 3659 - 3673[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-06121 RAB Revue Centre de documentation En réserve L003 Disponible Agent-based modelling of shifting cultivation field patterns, Vietnam / M.R. Jepsen in International journal of geographical information science IJGIS, vol 20 n° 9 (october 2006)
[article]
Titre : Agent-based modelling of shifting cultivation field patterns, Vietnam Type de document : Article/Communication Auteurs : M.R. Jepsen, Auteur ; S. Leisz, Auteur ; K. Rasmussen, Auteur ; et al., Auteur Année de publication : 2006 Article en page(s) : pp 1067 - 1085 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse comparative
[Termes IGN] analyse de groupement
[Termes IGN] classification barycentrique
[Termes IGN] cultures
[Termes IGN] figure géométrique
[Termes IGN] image Landsat-TM
[Termes IGN] image Terra-ASTER
[Termes IGN] segmentation d'image
[Termes IGN] simulation
[Termes IGN] spatial metrics
[Termes IGN] surface cultivée
[Termes IGN] système multi-agents
[Termes IGN] utilisation du sol
[Termes IGN] Viet NamRésumé : (Auteur) Shifting cultivation in the Nghe An Province of Vietnam's Northern Mountain Region produces a characteristic land-cover pattern of small and larger fields. The pattern is the result of farmers cultivating either individually or in spatially clustered groups. Using spatially explicit agent-based modelling, and relying on empirical data from fieldwork and observations for parameterization of variables, the level of clustering in agricultural fields observed around a study village is reproduced. Agents in the model act to maximize labour productivity, which is based on potential yield and labour costs associated with fencing of fields, and are faced with physical constraints. The simulation results are compared with land-cover data obtained from remote sensing. Comparisons are made on patterns as detected visually and using the mean nearest-neighbour ratio. Baseline simulation outputs show high degrees of spatial clustering and similarity to the land-cover data, but also a need for further calibration of model variables and controls. Copyright Taylor & Francis Numéro de notice : A2006-424 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810600830848 En ligne : https://doi.org/10.1080/13658810600830848 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28148
in International journal of geographical information science IJGIS > vol 20 n° 9 (october 2006) . - pp 1067 - 1085[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-06091 RAB Revue Centre de documentation En réserve L003 Disponible 079-06092 RAB Revue Centre de documentation En réserve L003 Disponible Bridge detection in airborne laser scanner data / George Sithole in ISPRS Journal of photogrammetry and remote sensing, vol 61 n° 1 (October 2006)
[article]
Titre : Bridge detection in airborne laser scanner data Type de document : Article/Communication Auteurs : George Sithole, Auteur ; M. George Vosselman, Auteur Année de publication : 2006 Article en page(s) : pp 33 - 46 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] détection du bâti
[Termes IGN] données lidar
[Termes IGN] pont
[Termes IGN] segmentation d'image
[Termes IGN] semis de pointsRésumé : (Auteur) In a landscape bridges are ambiguous features in that they are extensions of the bare earth but they are also man made. Therefore, in a Digital Terrain Model (DTM) generation, depending on application it is necessary to keep or remove bridges. For this reason they have to be detected explicitly. A geometric bridge detection algorithm is proposed that is based on the idea that features can be detected in a landscape based on cross-sections (profiles) in a landscape. The topological information contained in the cross-sections are used to identify seed bridge points. The seed bridge points are then used to detect individual bridges. The bridge detection algorithm is novel in that the algorithm is blind to the shape of a bridge and is adaptable to different bridge designs. Therefore, bridges need not have parallel edges or uniform width. Furthermore, bridges can curve, split into parts, and contain holes. The bridge detection algorithm has been tested on various data sets and found to work very well in detecting bridges. Copyright ISPRS Numéro de notice : A2006-440 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2006.07.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2006.07.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28164
in ISPRS Journal of photogrammetry and remote sensing > vol 61 n° 1 (October 2006) . - pp 33 - 46[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-06071 SL Revue Centre de documentation Revues en salle Disponible Real-time monitoring and short-term forecasting of land surface phenology / M.A. White in Remote sensing of environment, vol 104 n° 1 (15/09/2006)
[article]
Titre : Real-time monitoring and short-term forecasting of land surface phenology Type de document : Article/Communication Auteurs : M.A. White, Auteur ; Ramakrishna R. Nemani, Auteur Année de publication : 2006 Article en page(s) : pp 43 - 49 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse diachronique
[Termes IGN] phénologie
[Termes IGN] prédiction
[Termes IGN] prévision à court terme
[Termes IGN] seuillage d'image
[Termes IGN] surface du sol
[Termes IGN] surveillance écologique
[Termes IGN] temps réelRésumé : (Auteur) Land surface phenology is an important process for real-time monitoring and short-term forecasting in diverse land management, health, and hydrologic modeling applications. Yet current efforts to characterize phenological processes are limited by remote sensing challenges and lack of uncertainty estimates. Here, for a global distribution of phenologically and climatically similar phenoregions, we used the Advanced Very High Resolution Radiometer to develop a conceptually and computationally simple technique for real-time and forecast applications. Our overall approach was to analyze the phenological behavior of groups of pixels without recourse to smoothing or fitting. We used a 3-step initial process: (1) define a phenoregion specific normalized difference vegetation index threshold; (2) for all days from 1982–2003, calculate the percent of pixels above the threshold (PAT); (3) calculate daily 1982–2003 empirical distributions of PAT. For real-time monitoring, the current PAT may then be compared to the historical range of variability and visualized in relation to user-defined levels. Using similar concepts, we projected daily PAT up to one month in the future and compared predicted and actual dates at which a hypothetical PAT was reached. We found that the maximum lead-time of phenological forecasts could be analytically defined for user-specified uncertainty levels. The approach is adaptable to different remote sensing technologies and provides a foundation for ascribing a sequence of ground conditions (e.g. snowmelt, vegetative growth, pollen production, insect phenology) to remotely sensed land surface phenology observations. Copyright Elsevier Numéro de notice : A2006-393 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2006.04.014 En ligne : https://doi.org/10.1016/j.rse.2006.04.014 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28117
in Remote sensing of environment > vol 104 n° 1 (15/09/2006) . - pp 43 - 49[article]Resolution dependent errors in remote sensing of cultivated areas / M. Ozdogan in Remote sensing of environment, vol 103 n° 2 (30/07/2006)
[article]
Titre : Resolution dependent errors in remote sensing of cultivated areas Type de document : Article/Communication Auteurs : M. Ozdogan, Auteur ; Curtis E. Woodcock, Auteur Année de publication : 2006 Article en page(s) : pp 203 - 217 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] analyse de sensibilité
[Termes IGN] Californie (Etats-Unis)
[Termes IGN] Chine
[Termes IGN] cultures
[Termes IGN] distribution spatiale
[Termes IGN] erreur de classification
[Termes IGN] image Ikonos
[Termes IGN] limite de résolution géométrique
[Termes IGN] précision infrapixellaire
[Termes IGN] seuillage d'image
[Termes IGN] surface cultivée
[Termes IGN] variogrammeRésumé : (Auteur) Remote sensing has become a common and effective method for estimating the areal coverage of land cover classes. One class of particular interest is agriculture as area estimates of cultivated lands are important for purposes such as estimating yields or irrigation needs. The synoptic coverage of satellite imagery and the relative ease of automated analysis have led to widespread mapping of agriculture using remote sensing. The accuracy of area estimates derived from these maps is known to be related to the accuracy of the maps. However, even in the situation where the map is very accurate, errors in area estimates may occur. These errors result from the behavior of the distribution of subpixel proportions of cultivated areas, and how that behavior changes as a result of sensor spatial resolution and class definitions. The sensitivity of estimates of cultivated areas to sensor spatial resolution and to the choice of threshold used to define cultivated land is explored in six agriculturally distinct locations around the world. Using a beta model for the distribution of subpixel proportions that is parameterized using variograms, it is possible to model the distribution of subpixel proportions for any spatial resolution. When the spatial resolution is small with respect to the spatial structure of the landscape (as measured by the variogram range) use of any class definition threshold produces an estimate very close to the true area coverage. On the other hand, as the resolution becomes coarse in relation to the variogram range, the subpixel proportions are no longer concentrated at the extremes of the distribution and the difference between the estimated and the true area has greater sensitivity to the selected threshold used to define classes. Thus, for the cases examined here, both the resolution and the class definition threshold have a strong influence on area estimates. The spatial resolutions where errors can be large depend on landscape spatial structure, which can be quantified using variograms. The net effect is that for the same spatial resolution, some places will exhibit much larger errors in area estimates than others. For the site in the Anhui province of China, where agricultural fields are very small (0.07 ha on the average), area estimates are highly sensitive to class definition thresholds even at the relatively fine resolution of 45 m. Conversely, in California (USA) spatial resolutions as coarse as 500 m can be used to reliably estimate cultivated areas. Results also suggest that the proportion of the total area that is cultivated significantly influences the accuracy of area estimates. When the area proportion is low, the class definition threshold must also be low to achieve an accurate area estimate. Conversely, in areas dominated by agriculture, a very stringent class definition of cultivated lands is required for accurate area estimates. While explored in the context of estimation of cultivated areas, the findings presented here are generic to the problem of area estimation using remote sensing. Copyright Elsevier Numéro de notice : A2006-321 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2006.04.004 En ligne : https://doi.org/10.1016/j.rse.2006.04.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28045
in Remote sensing of environment > vol 103 n° 2 (30/07/2006) . - pp 203 - 217[article]Creating a hydrographic network from its cartographic representation: a case study using Ordnance Survey mastermap data / Nicolas Regnauld in International journal of geographical information science IJGIS, vol 20 n° 6 (july 2006)PermalinkScale sets image analysis / Laurent Guigues in International journal of computer vision, vol 68 n°3 (July 2006)PermalinkHigh spatial resolution satellite imagery, DEM derivatives, and image segmentation for the detection of mass wasting processes / J. Barlow in Photogrammetric Engineering & Remote Sensing, PERS, vol 72 n° 6 (June 2006)PermalinkMapping built-up areas from multitemporal interferometric SAR images: a segment-based approach / Leena Matikainen in Photogrammetric Engineering & Remote Sensing, PERS, vol 72 n° 6 (June 2006)PermalinkAutomatic extraction of wind erosion obstacles by integration of GIS data, DSM and stereo images / Y. Zhang in International Journal of Remote Sensing IJRS, vol 27 n°7-8 (April 2006)PermalinkSegmentation of airborne laser scanning data using a slope adaptative neighbourhood / S. Filin in ISPRS Journal of photogrammetry and remote sensing, vol 60 n° 2 (April 2006)PermalinkDétection et reconstruction de facettes 3D par approche hiérarchique par régions, à partir de couples d'images satellite THR / Nesrine Chehata in Bulletin d'information scientifique et technique de l'IGN, n° 75 (mars 2006)PermalinkSegmentation multi-échelles d'images et applications / Laurent Guigues in Bulletin d'information scientifique et technique de l'IGN, n° 75 (mars 2006)PermalinkA new approach to the nearest-neighbour method to discover cluster features in overlaid spatial point processes / Tao Pei in International journal of geographical information science IJGIS, vol 20 n° 2 (february 2006)PermalinkNoise 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)PermalinkPermalinkAnalyse et traitement des images numériques / Philippe Destuynder (2006)PermalinkAutomatic reconstruction of industrial installations using point clouds and images / Tahir Rabbani Shah (2006)PermalinkCouplage de données laser aéroporté et photogrammétriques pour l'analyse de scènes tridimensionnelles / Frédéric Bretar (2006)PermalinkPostflood damage evaluation using landsat TM and ETM+ data integrated with DEM / M. Gianinetto in IEEE Transactions on geoscience and remote sensing, vol 44 n° 1 (January 2006)PermalinkSemi-automatic rural land cover classification from high-resolution remote sensing images = Classification semi-automatique du terrain en zone rurale par télédétection à haute résolution / Roger Trias-Sanz (2006)PermalinkAssessment of very high spatial resolution satellite image segmentations / A.P. Carleer in Photogrammetric Engineering & Remote Sensing, PERS, vol 71 n° 11 (November 2005)PermalinkSupervised image classification by contextual adaboost based on posteriors in neighborhoods / Ryuei Nishii in IEEE Transactions on geoscience and remote sensing, vol 43 n° 11 (November 2005)PermalinkIntegrated shadow removal based on photogrammetry and image analysis / Y. Li in International Journal of Remote Sensing IJRS, vol 26 n° 18 (September 2005)PermalinkDe-shadowing of satellite/airborne imagery / R. Richter in International Journal of Remote Sensing IJRS, vol 26 n° 15 (August 2005)Permalink