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Sparse signal modeling: Application to image compression, Image error concealment and compressed sensing / Ali Akbari (2018)
Titre : Sparse signal modeling: Application to image compression, Image error concealment and compressed sensing Type de document : Thèse/HDR Auteurs : Ali Akbari, Auteur Editeur : Paris : Sorbonne Université Année de publication : 2018 Importance : 158 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse de Doctorat de Traitement du signal et de l’image, Sorbonne UniversitéLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] acquisition comprimée
[Termes IGN] compensation
[Termes IGN] compression d'image
[Termes IGN] modélisation
[Termes IGN] problème inverse
[Termes IGN] reconstruction d'image
[Termes IGN] représentation parcimonieuse
[Termes IGN] théorie du signalIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Signal models are a cornerstone of contemporary signal and image processing methodology. In this report, two particular signal modeling methods, called analysis and synthesis sparse representation, are studied which have been proven to be effective for many signals, such as natural images, and successfully used in a wide range of applications. Both models represent signals in terms of linear combinations of an underlying set, called dictionary, of elementary signals known as atoms. The driving force behind both models is sparsity of the representation coefficients, i.e. the rapid decay of the representation coefficients over the dictionary. On the other hands, the dictionary choice determines the success of the entire model. According to these two signal models, there have been two main disciplines of dictionary designing; harmonic analysis approach and machine learning methodology. The former leads to designing the dictionaries with easy and fast implementation, while the latter provides a simple and expressive structure for designing adaptable and efficient dictionaries. The main goal of this thesis is to provide new applications to these signal modeling methods by addressing several problems from various perspectives. It begins with the direct application of the sparse representation, i.e. image compression. The line of research followed in this area is the synthesis-based sparse representation approach in the sense that the dictionary is not fixed and predefined, but learned from training data and adapted to data, yielding a more compact representation. A new Image codec based on adaptive sparse representation over a trained dictionary is proposed, wherein different sparsity levels are assigned to the image patches belonging to the salient regions, being more conspicuous to the human visual system. Experimental results show that the proposed method outperforms the existing image coding standards, such as JPEG and JPEG2000, which use an analytic dictionary, as well as the state-of-the-art codecs based on the trained dictionaries. In the next part of thesis, it focuses on another important application of the sparse signal modeling, i.e. solving inverse problems, especially for error concealment (EC), wherein a corrupted image is reconstructed from the incomplete data, and Compressed Sensing recover, where an image is reconstructed from a limited number of random measurements. Signal modeling is usually used as a prior knowledge about the signal to solve these NP-hard problems. In this thesis, inspired by the analysis and synthesis sparse models, these challenges are transferred into two distinct sparse recovery frameworks and several recovery methods are proposed. Compared with the state-of-the-art EC and CS algorithms, experimental results show that the proposed methods show better reconstruction performance in terms of objective and subjective evaluations. This thesis is finalized by giving some conclusions and introducing some lines for future works. Note de contenu : 1- Introduction
2- Sparsity-based signal models
3- Image compressed sensing recovery
4- Receiver-based error concealment based on synthesis sparse recovery
5- Transmitter-based error concealment based on sparse recovery
6- Sparse representation-based image compression
7- Conclusion and future directionsNuméro de notice : 25937 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Spécialité : Traitement du signal et de l’image : Paris : 2018 nature-HAL : Thèse DOI : sans En ligne : http://www.theses.fr/2018SORUS461 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96286 Traitement et analyse des contraintes urbaines pour une optimisation morphologique : Etude comparative des modèles MorVer et SimPLU3D / Alia Belkaid (2018)
Titre : Traitement et analyse des contraintes urbaines pour une optimisation morphologique : Etude comparative des modèles MorVer et SimPLU3D Type de document : Article/Communication Auteurs : Alia Belkaid, Auteur ; Mickaël Brasebin , Auteur ; Ines Hassoumi, Auteur Editeur : [s.l.] : [s.n.] Année de publication : 2018 Conférence : TAIMA 2018, Traitement et Analyse de l'Information Méthodes et Applications 30/04/2018 05/05/2018 Hammamet Tunisie Note générale : bibliographie Langues : Français (fre) Descripteur : [Termes IGN] analyse spatiale
[Termes IGN] morphologie urbaine
[Termes IGN] optimisation (mathématiques)
[Termes IGN] programmation par contraintes
[Termes IGN] règlement
[Termes IGN] volume (grandeur)
[Termes IGN] zone urbaine
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) La morphologie urbaine est régulée par des règlements locaux d’urbanisme qui s’expriment à travers des textes. L’objectif de cet article est : i) de comparer deux modèles, SimPLU3D et MorVeR, qui traduisent les contraintes urbaines morphologiques en volumes, ii) et de relever les potentialités et les limites des deux approches informatiques. La mise en rapport des règles urbaines avec le volume contraint permet de distinguer le volume constructible optimal « géométriquement » du volume réglementaire qui optimise au mieux les contraintes urbaines.
Urban morphology is controlled by local planning regulations that are expressed through legal texts. The objective of this article is to compare two models, SimPLU3D and MorVeR, which transform the urban morphological constraints into volumes and to meet the potential and limitations of both computational approaches. The relation between the urban rules with the authorized volume leads to the optimal building volume "geometrically" regulatory volume which better optimizes the urban constraints.Numéro de notice : C2018-025 Affiliation des auteurs : LASTIG COGIT+Ext (2012-2019) Thématique : GEOMATIQUE/URBANISME Nature : Poster nature-HAL : Poster-avec-CL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90492 Documents numériques
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Traitement et analyse des contraintes urbaines ... - posterImage Jpeg Vector-based approach for combining ascending and descending persistent scatterers interferometric point measurements / Michael Foumelis in Geocarto international, vol 33 n° 1 (January 2018)
[article]
Titre : Vector-based approach for combining ascending and descending persistent scatterers interferometric point measurements Type de document : Article/Communication Auteurs : Michael Foumelis, Auteur Année de publication : 2018 Article en page(s) : pp 38 - 52 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] classification barycentrique
[Termes IGN] géodatabase
[Termes IGN] interferométrie différentielle
[Termes IGN] interpolation spatiale
[Termes IGN] modèle numérique de terrain
[Termes IGN] système d'information géographique
[Termes IGN] volcanRésumé : (Auteur) The combination of ascending and descending persistent scatterers interferometric (PSI) data by means of resampling and/or spatial interpolation, separately for each synthetic aperture radar geometry, is a commonly followed procedure, limited though by the reduced spatial coverage and the introduced uncertainties from multiple rasterization steps. Herein, an alternative approach is proposed for combining different PSI line-of-sight observables in the vector domain, based on the geographic proximity of PS point targets. In the proposed nearest neighbour vector approach all necessary analysis steps are performed by means of attributes transfer and calculations between features geodatabases, prior to any rasterization. By increasing the number of input point vectors during subsequent interpolation, the overall error budget coming from spatial interpolation is being reduced. The advantages of the proposed vector-based approach compared to the commonly used grid-based procedure are being demonstrated using real data. Numéro de notice : A2018-031 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2016.1222636 En ligne : https://doi.org/10.1080/10106049.2016.1222636 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89200
in Geocarto international > vol 33 n° 1 (January 2018) . - pp 38 - 52[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-2018011 RAB Revue Centre de documentation En réserve L003 Disponible Global, dense multiscale reconstruction for a billion points / Benjamin Ummenhofer in International journal of computer vision, vol 125 n° 1-3 (December 2017)
[article]
Titre : Global, dense multiscale reconstruction for a billion points Type de document : Article/Communication Auteurs : Benjamin Ummenhofer, Auteur ; Thomas Brox, Auteur Année de publication : 2017 Conférence : ICCV 2015, International Conference on Computer Vision 11/12/2015 18/12/2015 Santiago Chili OA Proceedings Article en page(s) : pp 82 - 94 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] carte de profondeur
[Termes IGN] discrétisation
[Termes IGN] maillage
[Termes IGN] méthode des éléments finis
[Termes IGN] octree
[Termes IGN] reconstruction 3D
[Termes IGN] reconstruction d'objetRésumé : (Auteur) We present a variational approach for surface reconstruction from a set of oriented points with scale information. We focus particularly on scenarios with nonuniform point densities due to images taken from different distances. In contrast to previous methods, we integrate the scale information in the objective and globally optimize the signed distance function of the surface on a balanced octree grid. We use a finite element discretization on the dual structure of the octree minimizing the number of variables. The tetrahedral mesh is generated efficiently with a lookup table which allows to map octree cells to the nodes of the finite elements. We optimize memory efficiency by data aggregation, such that robust data terms can be used even on very large scenes. The surface normals are explicitly optimized and used for surface extraction to improve the reconstruction at edges and corners. Numéro de notice : A2017-814 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article DOI : 10.1007/s11263-017-1017-7 En ligne : https://doi.org/10.1007/s11263-017-1017-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89256
in International journal of computer vision > vol 125 n° 1-3 (December 2017) . - pp 82 - 94[article]Large-scale block adjustment without use of ground control points based on the compensation of geometric calibration for ZY-3 images / Yang Bo in ISPRS Journal of photogrammetry and remote sensing, vol 134 (December 2017)
[article]
Titre : Large-scale block adjustment without use of ground control points based on the compensation of geometric calibration for ZY-3 images Type de document : Article/Communication Auteurs : Yang Bo, Auteur ; Wang Mi, Auteur ; Wen Xu, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1 - 14 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] angle de visée
[Termes IGN] compensation par bloc
[Termes IGN] corrélation automatique de points homologues
[Termes IGN] erreur systématique
[Termes IGN] étalonnage géométrique
[Termes IGN] image ZiYuan-3
[Termes IGN] méthode du gradient conjugué
[Termes IGN] modèle géométrique de prise de vue
[Termes IGN] point d'appui virtuel
[Termes IGN] points homologues
[Termes IGN] précision géométrique (imagerie)Résumé : (Auteur) The potential of large-scale block adjustment (BA) without ground control points (GCPs) has long been a concern among photogrammetric researchers, which is of effective guiding significance for global mapping. However, significant problems with the accuracy and efficiency of this method remain to be solved. In this study, we analyzed the effects of geometric errors on BA, and then developed a step-wise BA method to conduct integrated processing of large-scale ZY-3 satellite images without GCPs. We first pre-processed the BA data, by adopting a geometric calibration (GC) method based on the viewing-angle model to compensate for systematic errors, such that the BA input images were of good initial geometric quality. The second step was integrated BA without GCPs, in which a series of technical methods were used to solve bottleneck problems and ensure accuracy and efficiency. The BA model, based on virtual control points (VCPs), was constructed to address the rank deficiency problem caused by lack of absolute constraints. We then developed a parallel matching strategy to improve the efficiency of tie points (TPs) matching, and adopted a three-array data structure based on sparsity to relieve the storage and calculation burden of the high-order modified equation. Finally, we used the conjugate gradient method to improve the speed of solving the high-order equations. To evaluate the feasibility of the presented large-scale BA method, we conducted three experiments on real data collected by the ZY-3 satellite. The experimental results indicate that the presented method can effectively improve the geometric accuracies of ZY-3 satellite images. This study demonstrates the feasibility of large-scale mapping without GCPs. Numéro de notice : A2017-727 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.10.013 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.10.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88413
in ISPRS Journal of photogrammetry and remote sensing > vol 134 (December 2017) . - pp 1 - 14[article]Réservation
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