Descripteur
Termes IGN > mathématiques > analyse numérique > algèbre linéaire > calcul matriciel
calcul matricielSynonyme(s)algèbre matricielleVoir aussi |
Documents disponibles dans cette catégorie (260)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Titre : Efficiently acquiring reflectance fields using patterned illumination Type de document : Thèse/HDR Auteurs : Gaurav Garg, Auteur Editeur : Californie [USA] : Stanford University Année de publication : 2006 Importance : 100 p. Format : 21 x 30 cm Note générale : bibliographie
A dissertation submitted to the department of electrical engineering and the committee on graduate studies of Stanford University in partiall fulfillment of the requirements for the degree of Doctor of PhilosophyLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] dispersion
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] données 4D
[Termes IGN] éclairement lumineux
[Termes IGN] flux lumineux
[Termes IGN] matrice symétrique
[Termes IGN] réflectance
[Termes IGN] tenseurIndex. décimale : 24.30 Rayonnement électromagnétique Résumé : (auteur) The use of the reflectance fields of real world objects to render realistic looking images is rapidly increasing. The reflectance field describes the transport of light between the light incident on an object and the light exitant from it. This has numerous applications in areas that include entertainment, cultural heritage, digital libraries and space exploration. The central problem with this approach is the lack of fast methods to acquire the reflectance field data. This dissertation addresses this problem and describes a system for acquiring the reflectance field of real world objects that performs many orders of magnitude faster than the previous approaches. The system models the 8D reflectance field as a transport matrix between the 4D incident light field and the 4D exitant light field. It is a challenging task to measure this matrix because of its large size. However, in some cases the matrix is sparse, e.g. in scenes with little or no inter-reflections. To measure such matrices, this thesis describes a hierarchical technique called dual photography which exploits this sparseness to parallelize the acquisition process. This technique, however, performs poorly for scenes with significant diffuse inter-reflections because in such cases the matrix is dense. Fortunately, in these cases the matrix is often data-sparse. Data-sparseness refers to the fact that sub-blocks of the matrix can be well approximated using low-rank representations. Additionally, the transport matrix is symmetric. Symmetry enables simultaneous measurements from both sides, rows and columns, of the transport matrix. These measurements are used to develop a hierarchical acquisition algorithm that can exploit the data-sparseness by a local rank-1 approximation. This technique, called symmetric photography, parallelizes the acquisition for dense but data-sparse transport matrices. In the process, this thesis introduces the use of hierarchical tensors as the underlying data structure to represent data-sparse matrices, specifically through local rank-1 factorizations of the transport matrix. Besides providing an efficient representation for storage, it enables fast acquisition of the approximated transport matrix and fast rendering of the images from the captured matrix. The prototype acquisition system consists of an array of mirrors and a pair of coaxial projector and camera controlled by a computer. The effectiveness of the system is demonstrated with scenes rendered from reflectance fields that were captured by this system. In these renderings one can change the viewpoint as well as relight objects using arbitrary incident light fields. Note de contenu : 1- Introduction
2- Reflectance Field as the Light Transport Matrix
3- Dual Photography
4- Hierarchical Tensors
5- Symmetric Photography
6- Conclusions and Future WorkNuméro de notice : 24635 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère Note de thèse : PhD Thesis : Electrical engineering : Stanford University : 2006 DOI : sans En ligne : https://graphics.stanford.edu/papers/ggaurav_thesis/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92231 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 24635-01 THESE Livre LASTIG Dépôt en unité Exclu du prêt Fourier series and the cartographic line / G.J. Lawford in International journal of geographical information science IJGIS, vol 20 n° 1 (january 2006)
[article]
Titre : Fourier series and the cartographic line Type de document : Article/Communication Auteurs : G.J. Lawford, Auteur Année de publication : 2006 Article en page(s) : pp 31 - 52 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes IGN] Australie
[Termes IGN] données vectorielles
[Termes IGN] échelle cartographique
[Termes IGN] généralisation cartographique automatisée
[Termes IGN] matrice
[Termes IGN] reconnaissance de formes
[Termes IGN] segment de droite
[Termes IGN] série de Fourier
[Termes IGN] simplification de contour
[Termes IGN] système d'information géographique
[Termes IGN] trait de côte
[Termes IGN] transformation de FourierRésumé : (Auteur) The application of Fourier Series to cartography and GIS, in particular to shape analysis, fine simplification and enhancement, and the measurement of cartographic scale, is explored. Vector representations of the Australian coastline are manipulated using Fourier techniques and the output appraised in terms of its ability to encapsulate the shape of the original coastline, or as a simplified or enhanced version of the original. Using Fourier techniques on vector representations of parts of the Australian coastline at six different cartographic scales, a relationship between cartographic scale and line complexity is found to exist, and an empirical expression of that relationship developed. The intent of developing an empirical relationship is to bring greater consistency to the process of assigning cartographic scale to data, and thereby to the process of map production, data simplification and GIS analysis. Fourier techniques are found to be a poor encapsulator of cartographic shape, a good method of line simplification and enhancement, and a promising method of measuring cartographic scale. As background, some revision of the history and mathematics of Fourier Series, and previous research into the application of Fourier Series to cartography, is given. Numéro de notice : A2006-024 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/13658810512331319109 En ligne : https://doi.org/10.1080/13658810512331319109 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27751
in International journal of geographical information science IJGIS > vol 20 n° 1 (january 2006) . - pp 31 - 52[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-06011 RAB Revue Centre de documentation En réserve L003 Disponible 079-06012 RAB Revue Centre de documentation En réserve L003 Disponible A generalized cross-tabulation matrix to compare soft-classified maps at multiple resolutions / Robert Gilmore Pontius in International journal of geographical information science IJGIS, vol 20 n° 1 (january 2006)
[article]
Titre : A generalized cross-tabulation matrix to compare soft-classified maps at multiple resolutions Type de document : Article/Communication Auteurs : Robert Gilmore Pontius, Auteur ; L. Cheuk, Auteur Année de publication : 2006 Article en page(s) : pp 1 - 30 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] algèbre de Boole
[Termes IGN] classification pixellaire
[Termes IGN] données multiéchelles
[Termes IGN] matrice
[Termes IGN] numérisation
[Termes IGN] système d'information géographiqueRésumé : (Auteur) This paper addresses two grand challenges in the development of methods for Geographic Information Science (GIS). First, this paper presents techniques to compute a cross-tabulation matrix for soft-classified pixels. Second, it shows how to compute the cross-tabulation matrix at multiple scales. The traditional approach to construct the cross-tabulation matrix uses a Boolean operator to analyse pixels that are hard-classified. For soft-classified pixels, the contemporary approach uses a Multiplication operator ; the fuzzy approach uses a Minimum operator ; whereas this paper proposes a multiple-resolution approach that uses a Composite operator. There are difficulties with the traditional, contemporary, and fuzzy methods of computing the cross-tabulation matrix. The proposed multiple-resolution method resolves those difficulties. Furthermore, the proposed method facilitates multiple-resolution analysis, so it can examine how results change as a function of scale. The paper derives the equations to compute cross-tabulation matrices at multiple resolutions and connects those equations to ontological foundations of GIS. Numéro de notice : A2006-023 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810500391024 En ligne : https://doi.org/10.1080/13658810500391024 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27750
in International journal of geographical information science IJGIS > vol 20 n° 1 (january 2006) . - pp 1 - 30[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-06011 RAB Revue Centre de documentation En réserve L003 Disponible 079-06012 RAB Revue Centre de documentation En réserve L003 Disponible A hybrid interpolation method for the refinement of a regular grid digital elevation model / W.Z. Shi in International journal of geographical information science IJGIS, vol 20 n° 1 (january 2006)
[article]
Titre : A hybrid interpolation method for the refinement of a regular grid digital elevation model Type de document : Article/Communication Auteurs : W.Z. Shi, Auteur ; Yuan Tian, Auteur Année de publication : 2006 Article en page(s) : pp 53 - 67 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] grille régulière
[Termes IGN] interpolation linéaire
[Termes IGN] interpolation non-linéaire
[Termes IGN] matrice
[Termes IGN] modèle numérique de surface
[Termes IGN] système d'information géographiqueRésumé : (Auteur) A digital elevation model (DEM), which is used to represent a terrain surface. is normally constructed by applying an interpolation method on given sample elevation points. Interpolation methods can be classified into two classes: linear methods, which have a low time cost and are suitable for terrains where there is little change in elevation, and non-linear methods, which normally consume comparatively more time and are more suitable for terrains where there are frequent changes in elevation. A hybrid interpolation method, which involves both a linear method and a non-linear method of interpolation, is proposed in this paper. The proposed method aims to integrate the advantages of both linear and non-linear interpolation methods for the refinement of regular grid DEM. Here, the bilinear is identified as the linear method, and the bi-cubic is taken to be the non-linear interpolation method. The hybrid method is an integration of a linear model and non-linear interpolation model with a parameter that defines the weights for each of the models. The parameter is dependent on the complexity of the terrain, for which a DEM is to be interpolated. The experimental results in this study demonstrate that the hybrid method is effective for interpolating DEMs for various types of terrain. Numéro de notice : A2006-025 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810500286943 En ligne : https://doi.org/10.1080/13658810500286943 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27752
in International journal of geographical information science IJGIS > vol 20 n° 1 (january 2006) . - pp 53 - 67[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-06011 RAB Revue Centre de documentation En réserve L003 Disponible 079-06012 RAB Revue Centre de documentation En réserve L003 Disponible Further developments of a fuzzy set map comparison approach / Alex Hagen-Zanker in International journal of geographical information science IJGIS, vol 19 n° 7 (august 2005)
[article]
Titre : Further developments of a fuzzy set map comparison approach Type de document : Article/Communication Auteurs : Alex Hagen-Zanker, Auteur ; B. Straatman, Auteur ; I. Uljee, Auteur Année de publication : 2005 Article en page(s) : pp 769 - 785 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse comparative
[Termes IGN] carte numérique
[Termes IGN] classification dirigée
[Termes IGN] données maillées
[Termes IGN] estimation de précision
[Termes IGN] Kappa de Cohen
[Termes IGN] logique floue
[Termes IGN] matriceRésumé : (Auteur) Fuzzy set map comparison offers a novel approach to map comparison. The approach is specifically aimed at categorical raster maps and applies fuzzy set techniques, accounting for fuzziness of location and fuzziness of category, to create a similarity map as well as an overall similarity statistic: the Fuzzy Kappa. To date, the calculation of the Fuzzy Kappa (or K-fuzzy) has not been formally derived, and the documented procedure was only valid for cases without fuzziness of category. Furthermore, it required an infinitely large, edgeless map. This paper presents the full derivation of the Fuzzy Kappa; the method is now valid for comparisons considering fuzziness of both location and category and does not require further assumptions. This theoretical completion opens opportunities for use of the technique that surpass the original intentions. In particular, the categorical similarity matrix can be applied to highlight or disregard differences pertaining to selected categories or groups of categories and to distinguish between differences due to omission and commission. Numéro de notice : A2005-354 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810500072137 En ligne : https://doi.org/10.1080/13658810500072137 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27490
in International journal of geographical information science IJGIS > vol 19 n° 7 (august 2005) . - pp 769 - 785[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-05071 RAB Revue Centre de documentation En réserve L003 Disponible 079-05072 RAB Revue Centre de documentation En réserve L003 Disponible Modélisation d'un réseau de mares et évaluation de la connectivité selon la théorie des graphes / A. Thulie in Géomatique expert, n° 41- 42 (01/03/2005)PermalinkAlgèbre linéaire et géométrie / Luc Jolivet (2005)PermalinkDetection of buried targets via active selection of labeled data: Application to sensing subsurface UXO / Y. Zhang in IEEE Transactions on geoscience and remote sensing, vol 42 n° 11 (November 2004)PermalinkWavelet for urban spatial feature discrimination: comparisons with fractal, spatial autocorrelation, and spatial co-occurrence approaches / Nina S.N. Lam in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 7 (July 2004)PermalinkNonparametric weighted feature extraction for classification / D.A. Landgrebe in IEEE Transactions on geoscience and remote sensing, vol 42 n° 5 (May 2004)PermalinkSpeckle filtering and coherence estimation of polarimetric SAR interferometry data for forest applications / Jong-Sen Lee in IEEE Transactions on geoscience and remote sensing, vol 41 n° 10 (October 2003)PermalinkAlgèbre linéaire / Henri Roudier (2003)PermalinkSolutions for exterior orientation in photogrammetry: a review / Pierre Grussenmeyer in Photogrammetric record, vol 17 n° 100 (October 2002 - March 2003)PermalinkAdaptation du modèle orbitographique Spot 4 aux satellites / J.C. Clerget (2002)PermalinkZur Berücksichtigung der geometrischen Objektunsicherheit in der Geoinformatik / Michael Glemser (2001)Permalink