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Generation of hyperspectral digital surface model in forest areas using hyperspectral 2D frame camera onboard RPAS / Geração de modelo digital de superfície hiperespectral, em áreas de floresta utilizando câmara hiperespectral de quadro embarcada em VANTOliveira, Raquel Alves de [UNESP] 29 June 2017 (has links)
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Previous issue date: 2017-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Recentemente, os sensores hiperespectrais miniaturizados entraram no mercado e alguns modelos adquirem bandas hiperespectrais com geometria de quadro, com a vantagem de serem também operados em veículos aéreos remotamente pilotados (VARP). As imagens deste tipo de câmara podem ser utilizadas para a geração de modelos digitais de superfície hiperespectral (MDSHs) de alta resolução, usando o VARP, sem a necessidade do registro de dados de diferentes sensores ou diferente datas de aquisição. MDSHs aumentam o conhecimento sobre os alvos, uma vez que permitem modelar a reflectância do alvo utilizando dados provenientes de diferentes direções. Neste trabalho, a câmara hiperespectral de quadro utilizada não adquire todas as bandas instantaneamente, causando um deslocamento entre as bandas devido ao movimento da plataforma. Os principais objetivos deste projeto foram estudar e desenvolver técnicas para a geração de MDSHs em áreas de florestas, investigando e avaliando as principais etapas para o processamento das imagens da câmara hiperespectral de quadro até a geração do MSDH. Considerando que a tecnologia da câmara baseia-se em filtros ajustáveis, o estudo avaliou: a auto-calibração da câmara, verificando o comportamento dos parâmetros de orientação interior em diferentes bandas espectrais; o corregistro das bandas através de transformações geométricas 2D; e a estimativa dos parâmetros de orientação exterior. Em relação à geração do MDS, uma abordagem baseada em correspondência de imagem no espaço do objeto foi desenvolvida, adaptando o método de busca em linha vertical (VLL) para a geração MDSH e foi nomeado como VLL hiperespectral (HVLL). Adicionalmente, o uso de imagens classificadas para a adaptação dos parâmetros de correspondência foi avaliado com o objetivo de melhorar o processo de correspondência para diferentes objetos (HVLLC). Posteriormente, foram utilizadas múltiplas bandas no processo de correspondência de imagens, dados como múltiplos ângulos de visada e informação espectral foram calculados simultaneamente ao processo de correspondência de imagens. A avaliação da qualidade foi realizada comparando-se os MDSs gerados com os produzidos por um software comercial e por dados Airborne Laser Scanning (ALS). Esta investigação demonstrou que a técnica proposta pode ser usada para a geração de modelos 3D integrados aos dados hiperespectrais multiangulares da câmara hiperespectral de quadro. A avaliação de todas as etapas demonstrou que esta tecnologia pode fornecer dados geométricos e espectrais precisos e os MDSHs resultantes possuem potencial para várias aplicações de sensoriamento remoto. / Recently, miniaturized hyperspectral sensors, operable from small Remotely Piloted Aerial Systems (RPAS), have entered the market and some of these sensors acquire hyperspectral bands in frame geometry. Images of the lightweight hyperspectral 2D frame camera can be used to generate high-resolution hyperspectral digital surface models (HDSMs), without the registration of data from different sensors or different dates of acquisition. HSDMs increase the knowledge about the targets since it allows modeling the target reflectance using data coming from different directions. In this study, the hyperspectral 2D frame camera used does not acquire all bands instantaneously, causing band misalignment due to the platform motion. The main aims of this project were to study and develop techniques for the generation of HDSMs in forest areas, studying and assessing the main steps to process the hyperspectral 2D frame camera images until the HDSM generation. Considering that the camera technology is based on tunable filters, the study have assessed the orientation and DSM generation steps: the self-calibrating bundle adjustment to verify the behaviour of the interior orientation parameters using different spectral bands; the co-registration of the bands using 2D geometric transformation; the exterior orientation parameter estimation. Regarding to the DSM generation, an approach based on object space image matching was developed, adapting the vertical line locus (VLL) method for HDSM generation, and was named as hyperspectral VLL (HVLL). Additionally, the use of image classification data was investigated in order to adapt the image matching parameters and improve the process of image matching for different objects (hyperspectral VLL classes - HVLLC). Further, multiple bands were used and the spectral and multiangular viewing geometry were computed simultaneously to the image matching method. Quality assessment was performed by comparing to DSMs generated to those produced by commercial software and also by Airborne Laser Scanning (ALS) data. This investigation demonstrated that the proposed technique can be used to generate integrated 3D information and multiangular hyperspectral data from hyperspectral 2D frame camera. The assessment of all steps showed that the hyperspectral 2D frame technology can provide accurate geometric and spectral data and the resulting HDSMs have potential for several remote sensing applications. / FAPESP: 2013/17787-3 / FAPESP: 2013/14444-0 / FAPESP: 2014/24844-6
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Improving Conventional Image-based 3D Reconstruction of Man-made Environments Through Line Cloud IntegrationGråd, Martin January 2018 (has links)
Image-based 3D reconstruction refers to the capture and virtual reconstruction of real scenes, through the use of ordinary camera sensors. A common approach is the use of the algorithms Structure from Motion, Multi-view Stereo and Poisson Surface Reconstruction, that fares well for many types of scenes. However, a problem that this pipeline suffers from is that it often falters when it comes to texture-less surfaces and areas, such as those found in man-made environments. Building facades, roads and walls often lack detail and easily trackable feature points, making this approach less than ideal for such scenes. To remedy this weakness, this thesis investigates an expanded approach, incorporating line segment detection and line cloud generation into the already existing point cloud-based pipeline. Texture-less objects such as building facades, windows and roofs are well-suited for line segment detection, and line clouds are fitting for encoding 3D positional data in scenes consisting mostly of objects featuring many straight lines. A number of approaches have been explored in order to determine the usefulness of line clouds in this context, each of them addressing different aspects of the reconstruction procedure.
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Low-dimensional data analysis and clustering by means of Delaunay triangulation / Analyse et clustering de données en basse dimension par triangulation de DelaunayRazafindramanana, Octavio 05 December 2014 (has links)
Les travaux présentés et discutés dans cette thèse ont pour objectif de proposer plusieurs solutions au problème de l’analyse et du clustering de nuages de points en basse dimension. Ces solutions s’appuyent sur l’analyse de triangulations de Delaunay. Deux types d’approches sont présentés et discutés. Le premier type suit une approche en trois-passes classique: 1) la construction d’un graphe de proximité contenant une information topologique, 2) la construction d’une information statistique à partir de ce graphe et 3) la suppression d’éléments inutiles au regard de cette information statistique. L’impact de différentes measures sur le clustering ainsi que sur la reconnaissance de caractères est discuté. Ces mesures s’appuyent sur l’exploitation du complexe simplicial et non pas uniquement sur celle du graphe. Le second type d’approches est composé d’approches en une passe extrayant des clusters en même temps qu’une triangulation de Delaunay est construite. / This thesis aims at proposing and discussing several solutions to the problem of low-dimensional point cloudanalysis and clustering. These solutions are based on the analysis of the Delaunay triangulation.Two types of approaches are presented and discussed. The first one follows a classical three steps approach:1) the construction of a proximity graph that embeds topological information, 2) the construction of statisticalinformation out of this graph and 3) the removal of pointless elements regarding this information. The impactof different simplicial complex-based measures, i.e. not only based on a graph, is discussed. Evaluation is madeas regards point cloud clustering quality along with handwritten character recognition rates. The second type ofapproaches consists of one-step approaches that derive clustering along with the construction of the triangulation.
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Reconstruction de formes tubulaires à partir de nuages de points : application à l’estimation de la géométrie forestière / Tubular shapes reconstruction from point clouds : applications to the forests geometryRavaglia, Joris 14 December 2017 (has links)
Le coeur de cette thèse porte sur la modélisation géométrique et introduit une méthode robuste d'extraction de formes tubulaires à partir de nuages de points. Nous avons choisi de tester nos méthodes dans le contexte applicatif de la foresterie pour mettre en valeur la robustesse de nos algorithmes.Nos méthodes intègrent les normales aux points, il est donc nécessaire de les pré-calculer. Notre premier développement a alors consisté à présenter une méthode rapide d'estimation de normales. Pour ce faire nous avons approximé localement la géométrie du nuage de points en utilisant des "patchs" lisses dont la taille s'adapte à la complexité locale des nuages de points.Nos travaux se sont ensuite concentrés sur l’extraction robuste de formes tubulaires dans des nuages de points occlus, bruités et de densité inhomogène. Nous avons développé une variante de la transformée de Hough que nous avons couplé à une proposition de contours actifs indépendants de leur paramétrisation. Notre méthode a été validée en environnement forestier pour reconstruire des troncs d'arbre afin d'en relever les qualités par comparaison à des méthodes existantes.La reconstruction de troncs d'arbre ouvre d'autres questions dont la segmentation des arbres d'une placette forestière. Nous proposons également une méthode de segmentation pour isoler les différents objets d'un jeu de données.Durant nos travaux nous avons utilisé des approches de modélisation pour répondre à des questions géométriques, et nous les avons appliqué à des problématiques forestières. Il en résulte un pipeline de traitements cohérent qui, bien qu'illustré sur des données forestières, est applicable dans des contextes variés. / The core of this thesis concerns geometric modelling and introduces a fast and robust method for the extraction of tubular shapes from point clouds. We chose to test our method in the difficult applicative context of forestry in order to highlight the robustness of our algorithms.Our methods integrate normal vectors, thus they have to be pre-computed. Our first development consisted in the development of a fast normal estimation method on point cloud. To do so, we locally approximated the point cloud geometry using smooth "patches" of points which size adapts to the local complexity of the point cloud geometry.We then focused our work on the robust extraction of tubular shapes from dense, occluded, noisy point clouds suffering from non-homogeneous sampling density. We developed a variant of the Hough transform and combined this research with a new definition of parametrisation-invariant active contours. We validated our method in complex forest environments with the reconstruction of tree stems to emphasize its advantages and compare it to existing methods.Tree stem reconstruction also opens new perspectives halfway in between forestry and geometry such as the segmentation of trees from a forest plot. Therefore we propose a segmentation approach capable of isolating objects inside a point cloud.During our work we used modelling approaches to answer geometric questions and we applied our methods to forestry problems. Therefore, our studies result in a processing pipeline adapted to forest point cloud analyses, but the general geometric algorithms we propose can also be applied in various contexts.
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Reconstruction de formes tubulaires à partir de nuages de points : application à l’estimation de la géométrie forestièreRavaglia, Joris January 2017 (has links)
Les capacités des technologies de télédétection ont augmenté exponentiellement au cours des dernières années : de nouveaux scanners fournissent maintenant une représentation géométrique de leur environnement sous la forme de nuage de points avec une précision jusqu'ici inégalée. Le traitement de nuages de points est donc devenu une discipline à part entière avec ses problématiques propres et de nombreux défis à relever. Le coeur de cette thèse porte sur la modélisation géométrique et introduit une méthode robuste d'extraction de formes tubulaires à partir de nuages de points. Nous avons choisi de tester nos méthodes dans le contexte applicatif difficile de la foresterie pour mettre en valeur la robustesse de nos algorithmes et leur application à des données volumineuses.
Nos méthodes intègrent les normales aux points comme information supplémentaire pour atteindre les objectifs de performance nécessaire au traitement de nuages de points volumineux.Cependant, ces normales ne sont généralement pas fournies par les capteurs, il est donc nécessaire de les pré-calculer.Pour préserver la rapidité d'exécution, notre premier développement a donc consisté à présenter une méthode rapide d'estimation de normales. Pour ce faire nous avons approximé localement la géométrie du nuage de points en utilisant des "patchs" lisses dont la taille s'adapte à la complexité locale des nuages de points.
Nos travaux se sont ensuite concentrés sur l’extraction robuste de formes tubulaires dans des nuages de points denses, occlus, bruités et de densité inhomogène. Dans cette optique, nous avons développé une variante de la transformée de Hough dont la complexité est réduite grâce aux normales calculées. Nous avons ensuite couplé ces travaux à une proposition de contours actifs indépendants de leur paramétrisation. Cette combinaison assure la cohérence interne des formes reconstruites et s’affranchit ainsi des problèmes liés à l'occlusion, au bruit et aux variations de densité. Notre méthode a été validée en environnement complexe forestier pour reconstruire des troncs d'arbre afin d'en relever les qualités par comparaison à des méthodes existantes.
La reconstruction de troncs d'arbre ouvre d'autres questions à mi-chemin entre foresterie et géométrie. La segmentation des arbres d'une placette forestière est l'une d’entre elles. C'est pourquoi nous proposons également une méthode de segmentation conçue pour contourner les défauts des nuages de points forestiers et isoler les différents objets d'un jeu de données.
Durant nos travaux nous avons utilisé des approches de modélisation pour répondre à des questions géométriques, et nous les avons appliqué à des problématiques forestières.Il en résulte un pipeline de traitements cohérent qui, bien qu'illustré sur des données forestières, est applicable dans des contextes variés. / Abstract : The potential of remote sensing technologies has recently increased exponentially: new sensors now provide a geometric representation of their environment in the form of point clouds with unrivalled accuracy. Point cloud processing hence became a full discipline, including specific problems and many challenges to face. The core of this thesis concerns geometric modelling and introduces a fast and robust method for the extraction of tubular shapes from point clouds. We hence chose to test our method in the difficult applicative context of forestry in order to highlight the robustness of our algorithms and their application to large data sets.
Our methods integrate normal vectors as a supplementary geometric information in order to achieve the performance goal necessary for large point cloud processing. However, remote sensing techniques do not commonly provide normal vectors, thus they have to be computed. Our first development hence consisted in the development of a fast normal estimation method on point cloud in order to reduce the computing time on large point clouds. To do so, we locally approximated the point cloud geometry using smooth ''patches`` of points which size adapts to the local complexity of the point cloud geometry.
We then focused our work on the robust extraction of tubular shapes from dense, occluded, noisy point clouds suffering from non-homogeneous sampling density. For this objective, we developed a variant of the Hough transform which complexity is reduced thanks to the computed normal vectors. We then combined this research with a new definition of parametrisation-invariant active contours. This combination ensures the internal coherence of the reconstructed shapes and alleviates issues related to occlusion, noise and variation of sampling density. We validated our method in complex forest environments with the reconstruction of tree stems to emphasize its advantages and compare it to existing methods.
Tree stem reconstruction also opens new perspectives halfway in between forestry and geometry. One of them is the segmentation of trees from a forest plot. Therefore we also propose a segmentation approach designed to overcome the defects of forest point clouds and capable of isolating objects inside a point cloud.
During our work we used modelling approaches to answer geometric questions and we applied our methods to forestry problems. Therefore, our studies result in a processing pipeline adapted to forest point cloud analyses, but the general geometric algorithms we propose can also be applied in various contexts.
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From images to point clouds:practical considerations for three-dimensional computer visionHerrera Castro, D. (Daniel) 04 August 2015 (has links)
Abstract
Three-dimensional scene reconstruction has been an important area of research for many decades. It has a myriad of applications ranging from entertainment to medicine. This thesis explores the 3D reconstruction pipeline and proposes novel methods to improve many of the steps necessary to achieve a high quality reconstruction. It proposes novel methods in the areas of depth sensor calibration, simultaneous localization and mapping, depth map inpainting, point cloud simplification, and free-viewpoint rendering.
Geometric camera calibration is necessary in every 3D reconstruction pipeline. This thesis focuses on the calibration of depth sensors. It presents a review of sensors models and how they can be calibrated. It then examines the case of the well-known Kinect sensor and proposes a novel calibration method using only planar targets.
Reconstructing a scene using only color cameras entails di_erent challenges than when using depth sensors. Moreover, online applications require real-time response and must update the model as new frames are received. The thesis looks at these challenges and presents a novel simultaneous localization and mapping system using only color cameras. It adaptively triangulates points based on the detected baseline while still utilizing non-triangulated features for pose estimation.
The thesis addresses the extrapolating missing information in depth maps. It presents three novel methods for depth map inpainting. The first utilizes random sampling to fit planes in the missing regions. The second method utilizes a 2nd-order prior aligned with intensity edges. The third method learns natural filters to apply a Markov random field on a joint intensity and depth prior.
This thesis also looks at the issue of reducing the quantity of 3D information to a manageable size. It looks at how to merge depth maps from multiple views without storing redundant information. It presents a method to discard this redundant information while still maintaining the naturally variable resolution.
Finally, transparency estimation is examined in the context of free-viewpoint rendering. A procedure to estimate transparency maps for the foreground layers of a multi-view scene is presented. The results obtained reinforce the need for a high accuracy 3D reconstruction pipeline including all the previously presented steps. / Tiivistelmä
Kolmiuloitteisen ympäristöä kuvaavan mallin rakentaminen on ollut tärkeä tutkimuksen kohde jo usean vuosikymmenen ajan. Sen sovelluskohteet ulottuvat aina lääketieteestä viihdeteollisuuteen. Väitöskirja tarkastelee 3D ympäristöä kuvaavan mallin tuottamisprosessia ja esittää uusia keinoja parantaa korkealaatuisen rekonstruktion tuottamiseen vaadittavia vaiheita. Työssä esitetään uusia menetelmiä etäisyyssensoreiden kalibrointiin, samanaikaisesti tapahtuvaan paikannukseen ja kartoitukseen, syvyyskartan korjaamiseen, etäisyyspistepilven yksinkertaistamiseen ja vapaan katselukulman kuvantamiseen.
Väitöskirjan ensi osa keskittyy etäisyyssensoreiden kalibrointiin. Työ esittelee erilaisia sensorimalleja ja niiden kalibrointia. Yleisen tarkastelun lisäksi keskitytään hyvin tunnetun Kinect-sensorin käyttämiseen, ja ehdotetaan uutta kalibrointitapaa pelkkiä tasokohteita hyväksikäyttäen. Pelkkien värikameroiden käyttäminen näkymän rekonstruointiin tuottaa erilaisia haasteita verrattuna etäisyyssensoreiden käyttöön kuvan muodostamisessa. Lisäksi verkkosovellukset vaativat reaaliaikaista vastetta. Väitös tarkastelee kyseisiä haasteita ja esittää uudenlaisen yhtäaikaisen paikannuksen ja kartoituksen mallin tuottamista pelkkiä värikameroita käyttämällä. Esitetty tapa kolmiomittaa adaptiivisesti pisteitä taustan pohjalta samalla kun hyödynnetään eikolmiomitattuja piirteitä asentotietoihin.
Työssä esitellään kolme uudenlaista tapaa syvyyskartan korjaamiseen. Ensimmäinen tapa käyttää satunnaispisteitä tasojen kohdentamiseen puuttuvilla alueilla. Toinen tapa käyttää 2nd-order prior kohdistusta ja intensiteettireunoja. Kolmas tapa oppii filttereitä joita se soveltaa Markov satunnaiskenttiin yhteisillä tiheys ja syvyys ennakoinneilla. Tämä väitös selvittää myös mahdollisuuksia 3D-information määrän pienentämiseen käsiteltävälle tasolle. Työssä selvitetään, kuinka syvyyskarttoja voidaan yhdistää ilman päällekkäisen informaation tallentamista. Työssä esitetään tapa jolla päällekkäisestä datasta voidaan luopua kuitenkin säilyttäen luonnollisesti muuttuva resoluutio.
Viimeksi, tutkimuksessa on esitetty läpinäkyvyyskarttojen arviointiproseduuri etualan kerroksien monikatselukulmanäkymissä vapaan katselukulman renderöinnin näkökulmasta. Saadut tulokset vahvistavat tarkan 3D-näkymän rakentamisliukuhihnan tarvetta sisältäen kaikki edellä mainitut vaiheet.
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3D Surface Analysis for the Automated Detection of Deformations on Automotive PanelsYogeswaran, Arjun January 2011 (has links)
This thesis examines an automated method to detect surface deformations on automotive panels for the purpose of quality control along a manufacturing assembly line.
Automation in the automotive manufacturing industry is becoming more prominent, but quality control is still largely performed by human workers. Quality control is important in the context of automotive body panels as deformations can occur along the assembly line such as inadequate handling of parts or tools around a vehicle during assembly, rack storage, and shipping from subcontractors. These defects are currently identified and marked, before panels are either rectified or discarded. This work attempts to develop an automated system to detect deformations to alleviate the dependence on human workers in quality control and improve performance by increasing speed and accuracy.
Some techniques make use of an ideal CAD model behaving as a master work, and panels scanned on the assembly line are compared to this model to determine the location of deformations. This thesis presents a solution for detecting deformations of various scales without a master work. It also focuses on automated analysis requiring minimal intuitive operator-set parameters and provides the ability to classify the deformations as dings, which are deformations that protrude from the surface, or dents, which are depressions into the surface.
A complete automated deformation detection system is proposed, comprised of a feature extraction module, segmentation module, and classification module, which outputs the locations of deformations when provided with the 3D mesh of an automotive panel. Two feature extraction techniques are proposed. The first is a general feature extraction technique for 3D meshes using octrees for multi-resolution analysis and evaluates the amount of surface variation to locate deformations. The second is specifically designed for the purpose of deformation detection, and analyzes multi-resolution cross-sections of a 3D mesh to locate deformations based on their estimated size. The performance of the proposed automated deformation detection system, and all of its sub-modules, is tested on a set of meshes which represent differing characteristics of deformations in surface panels, including deformations of different scales. Noisy, low resolution meshes are captured from a 3D acquisition, while artificial meshes are generated to simulate ideal acquisition conditions. The proposed system shows accurate results in both ideal situations as well as non-ideal situations under the condition of noise and complex surface curvature by extracting only the deformations of interest and accurately classifying them as dings or dents.
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Visual Tracking of Deformation and Classification of Object Elasticity with Robotic Hand ProbingHui, Fei January 2017 (has links)
Performing tasks with a robotic hand often requires a complete knowledge of the manipulated object, including its properties (shape, rigidity, surface texture) and its location in the environment, in order to ensure safe and efficient manipulation. While well-established procedures exist for the manipulation of rigid objects, as well as several approaches for the manipulation of linear or planar deformable objects such as ropes or fabric, research addressing the characterization of deformable objects occupying a volume remains relatively limited. The fundamental objectives of this research are to track the deformation of non-rigid objects under robotic hand manipulation using RGB-D data, and to automatically classify deformable objects as either rigid, elastic, plastic, or elasto-plastic, based on the material they are made of, and to support recognition of the category of such objects through a robotic probing process in order to enhance manipulation capabilities. The goal is not to attempt to formally model the material of the object, but rather employ a data-driven approach to make decisions based on the observed properties of the object, capture implicitly its deformation behavior, and support adaptive control of a robotic hand for other research in the future. The proposed approach advantageously combines color image and point cloud processing techniques, and proposes a novel combination of the fast level set method with a log-polar mapping of the visual data to robustly detect and track the contour of a deformable object in a RGB-D data stream. Dynamic time warping is employed to characterize the object properties independently from the varying length of the detected contour as the object deforms. The research results demonstrate that a recognition rate over all categories of material of up to 98.3% is achieved based on the detected contour. When integrated in the control loop of a robotic hand, it can contribute to ensure stable grasp, and safe manipulation capability that will preserve the physical integrity of the object.
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Datorstödda mättekniker i fält av sprickor i limträbalkarVorobyev, Alexey January 2012 (has links)
Cracks in wood are considered to be one of the major problems for products, which have been made from this material. Crack detection and its propagation methods should be revised and improved with application of modern techniques. Nowadays new measuring techniques like digital camera image processing, and 3-D laser scanning are available. This work describes computer aided in-field methods for registration cracks in wood, its propagation, and tracing dimensional stability of glued laminated beams. The benefits of different methods for supervision of wooden element as well as its limitations are discussed. / <p>Validerat; 20120608 (anonymous)</p>
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Modélisation géométrique à différent niveau de détails d'objets fabriqués par l'homme / Geometric modeling of man-made objects at different level of detailsFang, Hao 16 January 2019 (has links)
La modélisation géométrique d'objets fabriqués par l'homme à partir de données 3D est l'un des plus grands défis de la vision par ordinateur et de l'infographie. L'objectif à long terme est de générer des modèles de type CAO de la manière la plus automatique possible. Pour atteindre cet objectif, des problèmes difficiles doivent être résolus, notamment (i) le passage à l'échelle du processus de modélisation sur des données d'entrée massives, (ii) la robustesse de la méthodologie contre des mesures d'entrées erronés, et (iii) la qualité géométrique des modèles de sortie. Les méthodes existantes fonctionnent efficacement pour reconstruire la surface des objets de forme libre. Cependant, dans le cas d'objets fabriqués par l'homme, il est difficile d'obtenir des résultats dont la qualité approche celle des représentations hautement structurées, comme les modèles CAO. Dans cette thèse, nous présentons une série de contributions dans ce domaine. Tout d'abord, nous proposons une méthode de classification basée sur l'apprentissage en profondeur pour distinguer des objets dans des environnements complexes à partir de nuages de points 3D. Deuxièmement, nous proposons un algorithme pour détecter des primitives planaires dans des données 3D à différents niveaux d'abstraction. Enfin, nous proposons un mécanisme pour assembler des primitives planaires en maillages polygonaux compacts. Ces contributions sont complémentaires et peuvent être utilisées de manière séquentielle pour reconstruire des modèles de ville à différents niveaux de détail à partir de données 3D aéroportées. Nous illustrons la robustesse, le passage à l'échelle et l'efficacité de nos méthodes sur des données laser et multi-vues stéréo sur des scènes composées d'objets fabriqués par l'homme. / Geometric modeling of man-made objects from 3D data is one of the biggest challenges in Computer Vision and Computer Graphics. The long term goal is to generate a CAD-style model in an as-automatic-as-possible way. To achieve this goal, difficult issues have to be addressed including (i) the scalability of the modeling process with respect to massive input data, (ii) the robustness of the methodology to various defect-laden input measurements, and (iii) the geometric quality of output models. Existing methods work well to recover the surface of free-form objects. However, in case of manmade objects, it is difficult to produce results that approach the quality of high-structured representations as CAD models.In this thesis, we present a series of contributions to the field. First, we propose a classification method based on deep learning to distinguish objects from raw 3D point cloud. Second, we propose an algorithm to detect planar primitives in 3D data at different level of abstraction. Finally, we propose a mechanism to assemble planar primitives into compact polygonal meshes. These contributions are complementary and can be used sequentially to reconstruct city models at various level-of-details from airborne 3D data. We illustrate the robustness, scalability and efficiency of our methods on both laser and multi-view stereo data composed of man-made objects.
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