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Efficient edge-aware surface mesh reconstruction for urban scenes / András Bódis-Szomorú in Computer Vision and image understanding, vol 157 (April 2017)
Titre : Efficient edge-aware surface mesh reconstruction for urban scenes Type de document : Article/Communication Auteurs : András Bódis-Szomorú, Auteur ; Hayko Riemenschneider, Auteur ; Luc Van Gool, Auteur Année de publication : 2017 Article en page(s) : pp 3 - 24 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes descripteurs IGN] carte de profondeur
[Termes descripteurs IGN] données clairsemées
[Termes descripteurs IGN] données lidar
[Termes descripteurs IGN] données localisées 3D
[Termes descripteurs IGN] maillage par triangles
[Termes descripteurs IGN] modèle 3D de l'espace urbain
[Termes descripteurs IGN] modèle numérique de surface
[Termes descripteurs IGN] reconstruction d'objet
[Termes descripteurs IGN] scène urbaine
[Termes descripteurs IGN] segmentation d'image
[Termes descripteurs IGN] structure-from-motion
[Termes descripteurs IGN] triangulation de DelaunayRésumé : (auteur) We propose an efficient approach for building compact, edge-preserving, view-centric triangle meshes from either dense or sparse depth data, with a focus on modeling architecture in large-scale urban scenes. Our method constructs a 2D base mesh from a preliminary view partitioning, then lifts the base mesh into 3D in a fast vertex depth optimization. Different view partitioning schemes are proposed for imagery and dense depth maps. They guarantee that mesh edges are aligned with crease edges and discontinuities. In particular, we introduce an effective plane merging procedure with a global error guarantee in order to maximally compact the resulting models. Moreover, different strategies for detecting and handling discontinuities are presented. We demonstrate that our approach provides an excellent trade-off between quality and compactness, and is eligible for fast production of polyhedral building models from large-scale urban height maps, as well as, for direct meshing of sparse street-side Structure-from-Motion (SfM) data. Numéro de notice : a2017-431 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : https://doi.org/10.1016/j.cviu.2016.06.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86332
in Computer Vision and image understanding > vol 157 (April 2017) . - pp 3 - 24[article]
Titre : Level of detail in 3D city models Type de document : Thèse/HDR Auteurs : Filip Biljecki, Auteur ; Jantien E. Stoter, Auteur ; Hugo Ledoux, Auteur Editeur : Delft [Pays-Bas] : Delft University of Technology Année de publication : 2017 Note générale : bibliographie
Doctoral dissertation, Delft university of technologyLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées
[Termes descripteurs IGN] analyse de sensibilité
[Termes descripteurs IGN] bâtiment
[Termes descripteurs IGN] CityGML
[Termes descripteurs IGN] erreur en position
[Termes descripteurs IGN] modèle 3D de l'espace urbain
[Termes descripteurs IGN] niveau de détail
[Termes descripteurs IGN] propagation d'erreur
[Termes descripteurs IGN] SIG 3D
[Termes descripteurs IGN] spécificationRésumé : (auteur) The concept of level of detail (LOD) describes the content of 3D city models and it plays an essential role during their life cycle. On one hand it comes akin to the concepts of scale in cartography and LOD in computer graphics, on the other hand it is a standalone concept that requires attention. LOD has an influence on tendering and acquisition, and it has a hand in storage, maintenance, and application aspects. However, it has not been significantly researched, and this PhD thesis fills this void. This thesis reviews dozens of current LOD standards, revealing that most practitioners consider the LOD to be comprised solely of the geometric detail of data and there are disparate views on the concept as a whole. However, the research suggests that the LOD encompasses additional metrics, such as semantics and texture. The thesis formalises the concept, enabling integration and comparison of current LOD standards. The established framework may be applied to cartography and to different forms of 3D geoinformation such as point clouds. Following the formalised concept, a new LOD specification is presented improving the LOD concept in the current OGC CityGML 2.0 standard, a prominent norm in the 3D GIS industry. The specification introduces 16 LODs for buildings that are shaped after analysing the capabilities of acquisition techniques and a large number of real-world datasets. The improved LOD specification may be integrated in product portfolios and tenders, preventing misunderstandings between stakeholders, and as a better language for communicating the specifics of a dataset to be acquired. The specification also considers different approaches to realise the data. Such geometric references result in dozens of different variants of the same LOD.3D data according to the LOD specification was generated using a procedural modelling engine that was developed over the course of the research. The engine is capable of producing 3D city models in a large number of different variants and according to the CityGML standard. The thesis also catalogues the many different ways to create 3D city models. A prominent technique for producing data in a different LOD is generalisation, i.e. simplifying a 3D city model. The inverse---augmenting the LOD of a dataset---has not been researched to a great extent, and this thesis gives an overview of the topic. This research demonstrates that it is possible to generate 3D city models without elevation measurements, inherently augmenting the LOD of coarser data (2D footprints). The method relies on machine learning: several attributes found in 2D datasets may hint at the height of a building, thus enabling extrusion and creating 3D city models suited for several applications.Some acquisition techniques may result in multi-LOD datasets, and nowadays there are some regions represented in different, independent datasets. However, it was found that possibilities to link such data are deficient. The lack of linking mechanisms inhibits acquisition, storage, and maintenance of multi-LOD data. Two methods for linking features across two or more LODs have been developed resulting in an increased consistency of multi-LOD datasets. The first method links matching geometries across multiple LODs, while the second method establishes a 4D data structure in which the LOD is modelled as the fourth (spatial) dimension.It is often believed that the more detailed 3D data the better. However, similarly as in computer graphics, dealing with data at fine LODs comes at a cost: such datasets are harder to obtain, their storage footprint is large, and their usage within a spatial analysis may be slow. Scarce research has been dedicated to investigating whether an increase in the LOD of the data brings a comparably significant increase in benefits when the data is used in a spatial analysis.First, an analysis using real-world multi-LOD data was carried out. Different LODs of spatial data covering the Netherlands was used in a spatial analysis to refine population maps, obtaining different results for each LOD. However, several problems are exposed, revealing that using real data for such investigations is not optimal.The remainder of the research focuses on using procedurally generated data for such experiments. Synthetic data in several different LODs has been generated and employed for four spatial analyses (estimation of the building shadow, envelope area, volume, and solar irradiation). The experiments result in different conclusions. Finer LODs usually bring some improvement to the quality of the spatial analysis, but not always and such may be negligible. The results of the experiments ultimately depend on the spatial analysis that is considered. The varying results between different spatial analyses make each of them unique. Furthermore, the benefit a finer LOD brings to a spatial analysis is not always clear and easily measurable. In short, striving to produce data at finer LODs may please the eye, but this is not always counter-balanced in the benefit it brings to a spatial analysis.A further addition to the equation above is that when realised, 3D city models are unavoidably burdened with acquisition errors. An error propagation analysis was performed by disturbing the procedurally generated datasets with a range of simulated positional errors. Comparisons have been made between the intentionally degraded datasets and their error-free counterparts, thus obtaining the magnitude of uncertainty the positional errors cause in a spatial analysis. Based on these experiments, several findings are discovered, most importantly:1. How the LODs are realised (which geometric references are used) has a larger influence than the LOD. A coarse LOD produced with a favourable geometric reference may yield better results than a finer LOD realised with an unfavourable reference.2. Positional errors considerably affect spatial analyses. The effect is comparable across similar LODs. Simpler LODs are sligthly less affected by positional errors, but they may contain a large systematic error.3. Errors induced in the acquisition process generally cancel out the improvement provided by finer LODs. The main conclusion is that in the considered spatial analyses the positional error has a significantly higher impact than the LOD. As a consequence, it is suggested that it is pointless to acquire geoinformation at a fine LOD if the acquisition method is not accurate, and instead it is advised to focus on the improvement of accuracy of the data. The thesis proposes additional research for future work. For example, since this research focuses specifically on 3D building models, it would be worth extending the research to other urban features such as roads and vegetation. Furthermore, quality control in 3D GIS does not encompass the evaluation of the LOD of data. Hence integration of the LOD in quality standards should be a priority for future work. Note de contenu : 1- Introduction
2- Background
3- Formalisation of LOD
4- Designing an LOD specification for buildings
5- Variants of LODs
6- Realisation of the specification
7- Generating 3D city models without elevation data
8- Managing multi-LOD data
9- Influence of LOD on spatial analyses (I)
10- Influence of LOD on spatial analyses (II)
11- Sensitivity of LOD to positional errors
12- Combining LOD and positional errors
13- Conclusions and future prospectsNuméro de notice : 17541 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Thèse étrangère Note de thèse : Doctoral dissertation : : Delft university of technology : 2017 DOI : 10.4233/uuid:f12931b7-5113-47ef-bfd4-688aae3be248 En ligne : https://repository.tudelft.nl/islandora/object/uuid%3Af12931b7-5113-47ef-bfd4-68 [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91250
Titre : Modélisation géométrique de scènes urbaines par imagerie satellitaire Type de document : Thèse/HDR Auteurs : Liuyun Duan, Auteur ; Florent Lafarge, Directeur de thèse Editeur : Nice : Université de Nice - Sophia Antipolis Année de publication : 2017 Format : 21 x 30 cm Note générale : Bibliographie
Thèse de doctorat en Automatique et traitement du signal et des images, École doctorale Sciences et technologies de l'information et de la communication (Sophia Antipolis, Alpes-Maritimes)Langues : Français (fre) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes descripteurs IGN] géomètrie algorithmique
[Termes descripteurs IGN] image satellite
[Termes descripteurs IGN] méthode de réduction d'énergie
[Termes descripteurs IGN] modèle 3D de l'espace urbain
[Termes descripteurs IGN] modélisation 3D
[Termes descripteurs IGN] partition d'image
[Termes descripteurs IGN] reconstruction 3D
[Termes descripteurs IGN] restitution numérique
[Termes descripteurs IGN] scène urbaine
[Termes descripteurs IGN] stéréoscopie
[Termes descripteurs IGN] urbanisme
[Termes descripteurs IGN] ville
[Termes descripteurs IGN] vision par ordinateurIndex. décimale : THESE Thèses et HDR Résumé : (auteur) La modélisation automatique de villes à partir d’images satellites est l'un des principaux défis en lien avec la reconstruction urbaine. Son objectif est de représenter des villes en 3D de manière suffisamment compacte et précise. Elle trouve son application dans divers domaines, qui vont de la planification urbaine aux télécommunications, en passant par la gestion des catastrophes. L'imagerie satellite offre plusieurs avantages sur l'imagerie aérienne classique, tels qu'un faible coût d'acquisition, une couverture mondiale et une bonne fréquence de passage au-dessus des sites visités. Elle impose toutefois un certain nombre de contraintes techniques. Les méthodes existantes ne permettent que la synthèse de DSM (Digital Surface Models), dont la précision est parfois inégale. Cette dissertation décrit une méthode entièrement automatique pour la production de modèles 3D compacts, précis et répondant à une sémantique particulière, à partir de deux images satellites en stéréo. Cette méthode repose sur deux grands concepts. D'une part, la description géométrique des objets et leur assimilation à des catégories génériques sont effectuées simultanément, conférant ainsi une certaine robustesse face aux occlusions partielles ainsi qu'à la faible qualité des images. D'autre part, la méthode opère à une échelle géométrique très basse, ce qui permet la préservation de la forme des objets, avec finalement, une plus grande efficacité et un meilleur passage à l'échelle. Pour générer des régions élémentaires, un algorithme de partitionnement de l'image en polygones convexes est présenté. Note de contenu : Texte intégral disponible le 21-04-2019 Numéro de notice : 21576 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de doctorat : Automatique et traitement du signal et des images : Sophia Antipolis : 2017 Organisme de stage : INRIA DOI : sans En ligne : http://www.theses.fr/2017AZUR4025 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90579
Titre : Relevé topographique des environnements urbains [article originellement paru dans le numéro mai/juin 2016 de la revue italienne GEOMedia] Type de document : Article/Communication Auteurs : Luigi Colombo, Auteur ; Barbara Marena, Auteur Année de publication : 2016 Article en page(s) : pp 46 - 55 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes descripteurs IGN] données GPS
[Termes descripteurs IGN] drone
[Termes descripteurs IGN] Italie
[Termes descripteurs IGN] modèle 3D de l'espace urbain
[Termes descripteurs IGN] modèle numérique de surface
[Termes descripteurs IGN] modèle numérique de terrain
[Termes descripteurs IGN] photographie aérienne
[Termes descripteurs IGN] précision centimétrique
[Termes descripteurs IGN] représentation multiple
[Termes descripteurs IGN] semis de points
[Termes descripteurs IGN] télémétrie laser terrestre
[Termes descripteurs IGN] visualisation 3DRésumé : (Auteur) Cet article se propose de détailler deux exemples de campagnes de levés menées en vue de constituer des modèles urbains 3D. Les techniques employées, qui ont permis de constituer automatiquement nuage de points et MNT, sont, d'une part, le scanner laser terrestre avec stationnement GPS, et, d'autre part, un survol par drone. Numéro de notice : A2016-967 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83658
in Géomatique expert > n° 113 (novembre - décembre 2016) . - pp 46 - 55[article]Réservation
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Titre : Automatic registration of MLS point clouds and SfM meshes of urban area Type de document : Article/Communication Auteurs : Reiji Yoshimura, Auteur ; Hiroaki Date, Auteur ; Satoshi Kanai, Auteur ; Ryohei Honma, Auteur ; Kazuo Oda, Auteur ; Tatsuya Ikeda, Auteur Année de publication : 2016 Article en page(s) : pp Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes descripteurs IGN] algorithme ICP
[Termes descripteurs IGN] données lidar
[Termes descripteurs IGN] données localisées 3D
[Termes descripteurs IGN] extraction de traits caractéristiques
[Termes descripteurs IGN] maille triangulaire
[Termes descripteurs IGN] méthode des moindres carrés
[Termes descripteurs IGN] modèle 3D de l'espace urbain
[Termes descripteurs IGN] Ransac (algorithme)
[Termes descripteurs IGN] similitude
[Termes descripteurs IGN] structure-from-motion
[Termes descripteurs IGN] zone urbaineRésumé : (auteur) Recent advances in 3D scanning technologies allow us to acquire accurate and dense 3D scan data of large-scale environments efficiently. Currently, there are various methods for acquiring large-scale 3D scan data, such as Mobile Laser Scanning (MLS), Airborne Laser Scanning, Terrestrial Laser Scanning, photogrammetry and Structure from Motion (SfM). Especially, MLS is useful to acquire dense point clouds of road and road-side objects, and SfM is a powerful technique to reconstruct meshes with textures from a set of digital images. In this research, a registration method of point clouds from vehicle-based MLS (MLS point cloud), and textured meshes from the SfM of aerial photographs (SfM mesh), is proposed for creating high-quality surface models of urban areas by combining them. In general, SfM mesh has non-scale information; therefore, scale, position, and orientation of the SfM mesh are adjusted in the registration process. In our method, first, 2D feature points are extracted from both SfM mesh and MLS point cloud. This process consists of ground- and building-plane extraction by region growing, random sample consensus and least square method, vertical edge extraction by detecting intersections between the planes, and feature point extraction by intersection tests between the ground plane and the edges. Then, the corresponding feature points between the MLS point cloud and the SfM mesh are searched efficiently, using similarity invariant features and hashing. Next, the coordinate transformation is applied to the SfM mesh so that the ground planes and corresponding feature points are adjusted. Finally, scaling Iterative Closest Point algorithm is applied for accurate registration. Experimental results for three data-sets show that our method is effective for the registration of SfM mesh and MLS point cloud of urban areas including buildings. Numéro de notice : A2016--116 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article En ligne : http://dx.doi.org/10.1080/10095020.2016.1212517 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84774
in Geo-spatial Information Science > vol 19 n° 3 (October 2016) . - pp[article]PermalinkPermalinkPermalinkPermalinkPermalinkPermalinkPermalinkPermalinkPermalinkPermalink
