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Réduction de la variance dans les sondages en présence d'information auxiliaire : une approche non paramétrique par splines de régression / Camélia Goga in Canadian journal of statistics (The), vol 33 n° 2 (June - August 2005)
[article]
Titre : Réduction de la variance dans les sondages en présence d'information auxiliaire : une approche non paramétrique par splines de régression Type de document : Article/Communication Auteurs : Camélia Goga, Auteur Année de publication : 2005 Article en page(s) : pp 1 - 18 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Statistiques
[Termes IGN] B-Spline
[Termes IGN] estimation statistique
[Termes IGN] méthode statistique
[Termes IGN] régression
[Termes IGN] varianceRésumé : (auteur) Nous traitons la prise en compte par un modèle non paramétrique de l’information auxiliaire afin d’améliorer en termes de variance l’estimateur d’un total. On introduit un nouveau type d’estimateur assisté par un modèle qui est basé sur les splines de régression. L’estimateur obtenu est une somme linéaire pondérée des valeurs de la variable d’intérêt avec des poids calés sur les totaux des fonctions B-splines. On montre également que sous certaines conditions, l’estimateur est asymptotiquement sans biais et convergent. Une approximation pour la variance sous le plan de sondage est donnée et nous prouvons que la variance anticipée est asymptotiquement équivalente à la borne inférieure de Godambe-Joshi. Le bon comportement de cet estimateur est vérifié par des simulations. Numéro de notice : IFN_6623 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE Nature : Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75614
in Canadian journal of statistics (The) > vol 33 n° 2 (June - August 2005) . - pp 1 - 18[article]
Titre : Automatic Digital Surface Model (DSM) generation from linear array images Type de document : Thèse/HDR Auteurs : Li Zhang, Auteur Editeur : Zurich : Institut für Geodäsie und Photogrammetrie IGP - ETH Année de publication : 2005 Collection : IGP Mitteilungen, ISSN 0252-9335 num. 88 Importance : 199 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-906467-55-9 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] appariement d'images
[Termes IGN] B-Spline
[Termes IGN] chambre DTC
[Termes IGN] filtre de Wallis
[Termes IGN] fonction de transfert de modulation
[Termes IGN] modèle numérique de surface
[Termes IGN] triangulation de DelaunayIndex. décimale : 35.20 Traitement d'image Résumé : (Auteur) This dissertation addresses the topic of automatic Digital Surface Model (DSM) generation from linear array images. Research on this issue is mainly motivated by the following facts: In recent years, CCD linear array sensors are widely used to acquire high-quality, high-resolution panchromatic and multispectral imagery for photogrammetric and remote sensing applications. Most of these sensors have the ability to acquire more than 2 views of the terrain surface during a single flight line or orbit. The processing of these kinds of images provides a challenge for algorithmic redesign and this opens the possibility to reconsider and improve many photogrammetric processing components. In particular, automatic DSM generation through image matching techniques is one of the main topics. Although this topic has gained much attention in the past years and a wide variety of approaches have been developed, the accuracy performance and the problems encountered are very similar in the major approaches and the performance of these approaches does by far not live up to the standards set by manual measurements. Therefore, efforts have to be made to develop a general framework for automatic DSM generation from linear array images, into which specific algorithms can be inserted easily, investigated and combined in order to achieve reasonable results in terms of precision and reliability.
In this dissertation, an image matching approach for automatic DSM generation from linear array images, which has the ability to provide dense, precise and reliable results is presented. The approach integrates different matching primitives, uses available and explicit knowledge concerning the image geometry and radiometry information, combines several image matching algorithms and automatic quality control, and works with a coarse-to-fine hierarchical matching strategy. The most outstanding characteristics are the efficient utilisation of multiple images and the integration of multiple matching primitives. With this approach, the linear array images and the given or previously triangulated orientation elements are taken as inputs. After pre-processing of the original images and production of the image pyramids, the matches of 3 kinds of features, i.e. feature points, grid points and edges, on the original resolution images are finally found progressively starting from the low density features on the images with the lowest resolution. An intermediate DSM is reconstructed from the matched features on each level of the pyramid by using the constrained Delauney triangulation method, which in turn is used in the subsequent pyramid level for the approximations and self-tuning of the matching parameters. Finally least squares matching methods are used to achieve more precise matches for al] the matched features and identify some false matches.
The presented approach essentially consists of several mutually connected components: the image pre-processing, the multiple primitive multi-image (MPM) matching, the refined matching and the system performance evaluation. Each of them is important and possesses particular features, which are fully elaborated in different parts of the dissertation.
First of all, a pre-processing method, which combines an adaptive smoothing filter and the Wallis filter, is used in order to reduce the effects of the inherent radiometric problems and optimize the images for subsequent feature extraction and image matching procedure. The method mainly consists of 3 processing stages. In the first stage, the noise characteristics of the images are analyzed quantitatively in both homogeneous and non-homogeneous image regions. The image blur problem (image unsharpness) is also addressed through the analysis of the image's Modulation Transfer Function (MTF). Then, an adaptive smoothing filter is applied to reduce the noise level and at the same time, to sharpen edges and preserve even fine detail such as corners and line end-points. Finally, the Wallis filter is applied to strongly enhance and sharpen the already existing texture patterns.
The MPM matching procedure is the core of our approach. In this approach, the matching is performed with the aid of multiple images, incorporating multiple matching primitives feature points, grid points and edges, integrating local and global image information and, utilizing a coarse-to-fine hierarchical matching strategy.
The MPM approach mainly consists of 3 integrated subsystems: point extraction and matching procedure, edge extraction and matching procedure and relational matching procedure. These 3 subsystems are followed through the image pyramid and the results at higher levels are used for guidance at the lower levels. At each pyramid level, the correspondence is established in two matching stages - locally and globally. In the local matching stage dense patterns of points and edges are matched. A unique and robust matching algorithm - The Geometrically Constrained Cross-Correlation (GC3 ) algorithm is employed to provide matching candidates for points and edge pixels. The algorithm. is based on the concept of multi-image matching guided from the object space and allows reconstruction of 3D objects by matching all the images at the same time, without having to go through the processing of all individual stereo-pairs and the merging of all stereo-pair results. The GC3 method, with the self-tuning of the parameters, leads to a reduction of problems caused by occlusions, multiple solutions and surface discontinuities. The global matching stage is responsible for imposing global consistency among the candidate matches in order to disambiguate the multiple candidates and avoid mismatches. The global matching is resolved by a probability relaxation based relational matching method. It uses the local support provided by points within a 2D neighbourhood. This corresponds to imposing a piecewise smoothness constraint, in which the matched edges serve as breaklines in order to prohibit the smoothness constraint crossing these edges and preserves the surface discontinuities.
The modified Multiphoto Geometrically Constrained Matching (MPGC) and the Least Squares B-Spline Snakes (LSB-Snakes) methods are used to achieve potentially sub-pixel accuracy matches and identify some inaccurate and possibly false matches. The DSM derived from the MPM module provides good enough approximations for these methods and increases the convergence rate. The initial values of the shaping parameters in MPGC matching can also be predetermined by using the image geometry and the derived DSM data. Finally, for each matched point, a reliability indicator is assigned based on the analysis of the matching results. For edges, a simplified version of the LSB-Snakes is implemented to match the edges, which are represented by parametric linear B-spline functions in object space. With this method, the parameters of linear B-spline functions of the edges in object space are directly estimated, together with the matching parameters in the image spaces of multiple images.
The system bas been tested extensively of linear array images with different image resolution and over different land cover types. The accuracy evaluation is based on the comparison between high quality DEMs/DSMs derived from airborne Laser Scanner or manual measurements and the automatically extracted DSMs. As evidenced by the visual inspection of the results, we can reproduce not only the general geomorphological features of the terrain relief, but also detailed features of relief. The results from the quantitative accuracy test indicate that the presented concept has the capability to give good and encouraging results. If the bias introduced by trees and buildings is taken out, we can expect a height accuracy of one pixel or even better from satellite imagery as "best case" scenario. In case of very high resolution TLS/SI images (footprint 8 cm and better) it is obvious that the "one pixel rule" cannot be maintained any more. Alone surface roughness and modeling errors will lead to larger deviations, such that an accuracy of 2 to 5 pixels should be considered an acceptable result.Numéro de notice : 13290 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère DOI : 10.3929/ethz-a-005055636 En ligne : http://dx.doi.org/10.3929/ethz-a-005055636 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54962 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 13290-01 35.20 Livre Centre de documentation Télédétection Disponible B-spline functions and wavelets for geographic line generalization / Eric Saux in Cartography and Geographic Information Science, vol 30 n° 1 (January 2003)
[article]
Titre : B-spline functions and wavelets for geographic line generalization Type de document : Article/Communication Auteurs : Eric Saux, Auteur Année de publication : 2003 Article en page(s) : pp 33 - 50 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] B-Spline
[Termes IGN] données multiéchelles
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] lissage de courbe
[Termes IGN] objet géographique linéaire
[Termes IGN] ondelette
[Termes IGN] polyligne
[Vedettes matières IGN] GénéralisationRésumé : (Auteur) Most line processing algorithms developed so far in cartographic generalization focus on polygonal curves (or polylines). This representation model is sometimes not sufficient for certain processes due to its lack of continuity or smoothness. Indeed, it may provide poor résults for lines having "smooth" initial shapes such as roads. Thus, we suggest using a modeling method based on B-spline curves. A maritime case study described in this paper shows that this representation provides good results at a fixed scale and is suitable for several automatic line cartographic generalization operators (smoothing, displacement, aggregation and compression). Lastly, we discuss the application of B-spline wavelets used in dealing with multiscaling. Numéro de notice : A2003-051 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304003100010938 En ligne : https://doi.org/10.1559/152304003100010938 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22347
in Cartography and Geographic Information Science > vol 30 n° 1 (January 2003) . - pp 33 - 50[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 032-03011 RAB Revue Centre de documentation En réserve L003 Disponible vol 62 n° 1 - January 2000 - Computer graphics international 1998 (CGI'98) conference, [actes], Hannover, June 22 to June 26, 1998 (Bulletin de Graphical models) / F. Wolter
[n° ou bulletin]
Titre : vol 62 n° 1 - January 2000 - Computer graphics international 1998 (CGI'98) conference, [actes], Hannover, June 22 to June 26, 1998 Type de document : Périodique Auteurs : F. Wolter, Éditeur scientifique ; N. Patrikalakis, Éditeur scientifique Année de publication : 2000 Conférence : CGI 1998, Computer graphics international 22/06/1998 26/06/1998 Hanovre Allemagne Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] approche hiérarchique
[Termes IGN] B-Spline
[Termes IGN] déformation de surface
[Termes IGN] encapsulation
[Termes IGN] polygonation
[Termes IGN] visualisationNuméro de notice : 095-0001 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Numéro de périodique Permalink : https://documentation.ensg.eu/index.php?lvl=bulletin_display&id=14337 [n° ou bulletin]Approximation hilbertienne / M. Atteia (1999)
Titre : Approximation hilbertienne : splines, ondelettes, fractales Type de document : Monographie Auteurs : M. Atteia, Auteur ; J. Gaches, Auteur Editeur : Les Ulis : EDP Sciences Année de publication : 1999 Collection : Grenoble Sciences Importance : 158 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-2-7061-0860-0 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Analyse numérique
[Termes IGN] approximation
[Termes IGN] B-Spline
[Termes IGN] espace de Hilbert
[Termes IGN] fonction spline
[Termes IGN] objet fractal
[Termes IGN] ondelette
[Termes IGN] Ploynôme
[Termes IGN] transformation de FourierRésumé : (Editeur) Splines, ondelettes et fractales sont des outils mathématiques très utilisés dans la pratique. L'objectif de l'ouvrage est d'expliquer l'origine de ces outils. Les premiers chapitres rappellent les connaissances de base telles les espaces de Hilbert et les séries de Fourier. Puis, utilisant les espaces classiques de Beppo Lévi et de Sobolev, on introduit la notion de noyau hilbertien. Ces noyaux hilbertiens permettent enfin d'élaborer les théories des splines, ondelettes et fractales. L'ouvrage n'est pas un simple traité : chaque chapitre est suivi d'exercices qui constituent un complément pour la compréhension des concepts et l'utilisation des outils. Numéro de notice : 18860 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55495 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18860-01 23.40 Livre Centre de documentation Mathématiques Disponible Contribution à la modélisation topologique par vision 2D et 3D pour la navigation d'un robot mobile sur terrain naturel / Carlos Alberto Parra Rodriguez (1999)PermalinkB-spline function analysis and design for high reliable DTM generation / F. Crosilla in GIS Geo-Informations-Systeme, vol 11 n° 4 (August 1998)PermalinkGeneralisation methods for propagating updates between cartographic data sets / Lars Harrie (1998)PermalinkGeodätische Hauptaufgaben auf Flächen in kartesischen Koordinaten / K. Aringer (1994)PermalinkA procedure for generating countour lines from a B-Spline surface / S.G. Satterfield in IEEE Computer graphics and applications, vol 5 n° 4 (April 1985)PermalinkB-Spline surfaces: a tool for computer painting / H. Huitric in IEEE Computer graphics and applications, vol 5 n° 3 (March 1985)PermalinkAufbau digitaler Höhenmodelle auf der Grundlage einfacher finiter Elemente / P. Reiss (1985)Permalink