Дисертації з теми "Modélisation de formes 3D"
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Klokov, Roman. "Deep learning pour la modélisation de formes 3D." Electronic Thesis or Diss., Université Grenoble Alpes, 2021. http://www.theses.fr/2021GRALM060.
Повний текст джерелаApplication of deep learning to geometric 3D data poses various challenges for researchers. The complex nature of geometric 3D data allows to represent it in different forms: occupancy grids, point clouds, meshes, implicit functions, etc. Each of those representations has already spawned streams of deep neural network models, capable of processing and predicting according data samples for further use in various data recognition, generation, and modification tasks.Modern deep learning models force researchers to make various design choices, associated with their architectures, learning algorithms and other specific aspects of the chosen applications. Often, these choices are made with the help of various heuristics and best practice methods discovered through numerous costly experimental evaluations. Probabilistic modeling provides an alternative to these methods that allows to formalize machine learning tasks in a meaningful manner and develop probability-based training objectives. This thesis explores combinations of deep learning based methods and probabilistic modeling in application to geometric 3D data.The first contribution explores how probabilistic modeling could be applied in the context of single-view 3D shape inference task. We propose a family of probabilistic models, Probabilistic Reconstruction Networks (PRNs),which treats the task as image conditioned generation and introduces a global latent variable, encoding shape geometry information. We explore different image conditioning options, and two different training objectives based on Monte Carlo and variational approximations of the model likelihood. Parameters of every distribution are predicted by multi-layered convolutional and fully-connected neural networks from the input images. All the options in the family of models are evaluated in the single-view 3D occupancy grid inference task on synthetic shapes and according image renderings from randomized viewpoints. We show that conditioning the latent variable prior on the input images is sufficient to achieve competitive and state-of-the-art single-view 3D shape inference performance for point cloud based and voxel based metrics, respectively. We additionally demonstrate that probabilistic objective based on variational approximation of the likelihood allows the model to obtain better results compared to Monte Carlo based approximation.The second contribution proposes a probabilistic model for 3D point cloud generation. It treats point clouds as distributions over exchangeable variables and use de Finetti’s representation theorem to define a global latent variable model with conditionally independent distributions for coordinates of each point. To model these point distributions a novel type of conditional normalizing flows is proposed, based on discrete coupling of point coordinate dimensions. These flows update the coordinates of each point sample multiple times by dividing them in two groups and inferring the updates for one group of coordinates from another group and, additionally, global latent variable sample by the means of multi-layered fully-connected neural networks with parameters shared for all the points. We also extend our Discrete Point Flow Networks (DPFNs) from generation to single-view inference task by conditioning the global latent variable prior in a manner similar to PRNs from the first contribution. Resulting generative performance demonstrates that DPFNs produce sets of samples of similar quality and diversity compared to state of the art based on continuous normalizing flows, but are approximately 30 times faster both in training and sampling. Results in autoencoding and single-view inference tasks show competitive and state-of-the-art performance for Chamfer distance, F-score and earth mover’s distance similarity metrics for point clouds
Anca, Alexe Iléana. "La modélisation interactive de formes 3D à partir d'esquisses." Toulouse 3, 2005. http://www.theses.fr/2005TOU30192.
Повний текст джерелаA prototyping process always starts with the production of several pencil sketches, which give a better description of the designer's idea before the 3D digital mockup is produced. It would be very challenging to integrate these tools into today's modeling software, in order to combine the sketch simplicity with the powerful 3D capabilities. We explore here the possibilities offered by gestural interface. The user is only provided with a digital pen and a digital tablet for his modeling task. Our approach is based on a double skeleton/3D implicit shape representation. For the implicit representation we propose new functions, and also a new boolean volume composition model. This representation allows modeling of a large topological variety of shapes with an adaptive level of detail and a rich collection of sketch based operations with precise control of the result. The surface is smooth, compact, and has a high class continuity level. The modeling operations are done in interactive time
Guillot, Olivier. "Maillage multirésolution de surfaces : modélisation et maillage de formes humaines 3D." La Rochelle, 2008. http://www.theses.fr/2008LAROS232.
Повний текст джерелаIn this thesis, we developped a surface subdivision that handles different kind of natural discontinuities of surfaces (darts, corners, creases and bounds) and the irregularities of the mesh that represents it. The aim of such a subdivision is to create limit surfaces that keep the natural discontinuities in order to enhance the quality of the multiresolution analysis based on that subdivision. We use the square root 3-subdivision because the resulting meshes grow slower. The multiresolution analysis by wavelets of a mesh of surface split the low frequencies and the higher ones, in order to obtain an approximation of the mesh and "details". Details can be truncated without creating great losses in the result of the synthesis. This property permits data compression of the details. Because the wavelet function is based on our square root 3-subdivision it handles natural discontinuities of the surfaces. This gives even smaller details for meshes with sharp edges. In order to analyse a mesh n times, this mesh must have a topology compatible with n subdivisions. If the surface contains discontinuities, n should be even. We built software tools in order to create a remeshing method that generates meshes compatible with those topologies. All this features are available in MEFP3C
Ben, Amor Boulbaba. "Contributions à la modélisation et à la reconnaissance faciales 3D." Ecully, Ecole centrale de Lyon, 2006. http://bibli.ec-lyon.fr/exl-doc/bbenamor.pdf.
Повний текст джерелаNowadays, face recognition represent one of the privileged fields of search due to the emergence of the security in many domains. This thesis lies within this scope, and more particularly, in the three-dimensional face recognition. In this work, we are interested to the complementary fields : 3D face modelling and recognition. Whereas modelling task aims at 3D face shape acquisition, recognition task aims at the identification of a probe face model among faces stored in a data base (gallery) or verify his identity. For that, two approaches are studied and implemented : (i) an hybrid approach for facial acquisition based on active vision and geometrical modelling, and (ii) an approach for aligning facial surfaces before computing similarities between 3D models. A new 3D face database is collected within the IV 2 French project in order to make signifiant experiments and evaluations of the developed algorithms
Entem, Even. "Interprétation et modélisation 3D automatique à partir de dessins au trait de formes organiques." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAM054/document.
Повний текст джерелаDrawing is the most common way to communicate about shapes.Thus, using sketching as a tool in the process of modeling 3D content is an attractive approach.However in the world of machines, drawings are still difficult to interpret as shape depictions.This has been the challenge tackled by many different research works since leveraging the little we know about perception is non trivial.My thesis focuses on pushing the limits of what can be inferred from single drawings of smooth shapes without any help from the user.In a first attempt we chose to select a category of shape namely animals and other creatures for which prior knowledge helps to solve the problem.Then we proposed to generalize parts of the solution to tackle the case of free form organic shapes.This manuscript thus presents the respective solutions we developed. The first one is able to infer plausible 3D models of animals from a single side-view sketch using anatomic principles to both interpret the drawing's elements and infer depth offsets between these elements.The second is an approach to decompose depictions of smooth shapes with non trivial cusp points into a set of structural parts' silhouettes ordered in depth, which can be used for editing and animation purposes.Many related ideas were explored on the way, and the ones presented in this manuscript leaves me confident about the future of this field of research
Selsis, Muriel. "Application des modèles de contours actifs au suivi et à la localisation 3D d'objets en mouvement." Lille 1, 1996. http://www.theses.fr/1996LIL10021.
Повний текст джерелаDecaudin, Philippe. "Modélisation par fusion de formes 3D pour la synthèse d'images : rendu de scènes 3D imitant le style "dessin animé"." Compiègne, 1996. http://www.theses.fr/1996COMPD938.
Повний текст джерелаIn the main section, we introduce new tools for modeling three¬dimensionnal objects for computer graphics. They allow interactive modeling of smooth shapes such as organic-looking shapes (animals, human bodies) and help animating and texturing them. A complex object is created by applying a succession of fusion and twist deformations to a simple object. The fusion tool allows deformation of the shape of the object by merging it with a simple 3D-shape (sphere, ellipsoid,. . . ); the object is deformed so that it embeds the simple shape. The twist tool allows creation of articulations which can be used to animate the deformable object. In a second section, we introduce a non-photorealistic rendering algorithm. It produces images having the appearance of a traditional cartoon from a 3D description of the scene (a static or an animated scene). The 3D scene is rendered with techniques allowing to outline the profiles and edges of objects, to color uniformly the patches, and to render shadows (self-shadows and projected-shadows) due to light sources
Allain, Benjamin. "Suivi volumétrique de formes 3D non rigides." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAM017/document.
Повний текст джерелаIn this thesis we propose algorithms for tracking 3D deformable shapes in motion from multiview video. Although series of reconstructed 3D shapes can be obtained by applying a static reconstruction algorithm to each temporal frame independently, such series do not represent motion. Instead, we want to provide a temporally coherent representation of the sequence of shapes resulting from temporal evolutions of a shape. Precisely, we want to represent the observed shape sequence as a 3D surface mesh whose vertices move in time but whose topology is constant.In contrast with most existing approaches, we propose to represent the motion of inner shape volumes, with the aim of better accounting for the volumetric nature of the observed object. We provide a fully volumetric approach to the fundamental problems of deformable shape tracking, which are the association between corresponding shape elements and the deformation model. In particular, we extend to a volumetric shape representation the EM-ICP tracking framework and the association-by-detection strategy.Furthermore, in order to better constrain the shape tracking problem, we propose a model for the temporal evolution of deformation. Our deformation model defines a shape space parametrized by variables that capture local deformation properties of the shape and whose values are automatically learned during the tracking process.We validate our tracking algorithms on several multiview video sequences with ground truth (silhouette and marker-based tracking). Our results are better or comparable to state of the art approaches.Finally, we show that volumetric tracking and the shape representation we choose can be leveraged for producing shape animations which combine captured and simulatated motion
Filali, Ansary Tarik. "Indexation de modèles 3D à partir de vues 2D." Evry, Institut national des télécommunications, 2006. http://www.theses.fr/2006TELE0006.
Повний текст джерелаThe management of big databases of three-dimensional models ( used in CAD applications, visualization, games, etc. ) is very important domain. The ability to characterize and easily retrieve 3D models is a key issue for the designers and the final users. In this frame, two main appoaches exist : search by example of a 3D model, and search by a 2D view or photo. In this thesis we focus ont he characterization of a 3D model by a set of views ( called characteristic views), and on the indexing process of the 3D models using theses characteristic views. In this thesis, we propose a new method for the selection of the " optimal" characteristic views set based on an informational criterion ( Bayesian information criteria). Starting from fact that all the views of a model 3D do not contain the same quantity of information about 3D model, we present a new bayesian approach for the indexing of the 3D models using their views. Our approach takes into account the probability of appreance of a 3D model and the importance of each of its view. Experiments carried on a database of 5000 3D models provided by Renault, within the framework of the RNRT SEMANTIC-D, show the good results of our method on mechanical objects. We compared our method with the most recent and relevant 3D models indexing methods using the standard database " Princeton Shape Benchmark". These experiments highlighted the very good results of our method compared with the ither approaches. To access our results and permit the test of our method, we made 3D search engine available online accessible using a PC or a PDA. Our searche engine permit the search for 3D objects using an example 3D model, a drawing or one or more photographs
Filbois, Alain. "Contributions à la modélisation automatique d'objets polyédriques 3D : extraction des primitives 3D, facettes et segments." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL075N.
Повний текст джерелаHergel, Jean. "Synthèse de formes fabricables à partir de spécifications partielles." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0003/document.
Повний текст джерелаThe Rapid Manufacturing techniques that emerged from Rapid Prototyping techniques such as 3D printing or laser cutting allow to fabricate unique objects. However, the design of those objects with existing CAD software remain a difficult task: rapid prototyping processes impose constraints on the geometry of the model. This thesis presents a set of techniques that assist the user in the design of an object by taking into account the constraints of the fabrication process. To achieve this, the algorithm automatically performs part of the modelling process. The following problems have been tackled: First, I propose to improve the quality of 3D printed objects by minimizing defects that appear during the fabrication. The technique developed impacts only the algorithm that drives the printer. Then, I propose to help the user to take into account the fabrication constraints during the modelling process. My techniques rely on partial information about the shape that the user wants to fabricate like the 2D sketch of a mechanism or a parametric model of a furniture. The algorithm optimizes the initial shape to improve fabrication objectives(Wastage, etc.) Finally, in some cases, the user does not know how to operate dedicated software. In this case, I propose a synthesis technique of furniture from functionnal specification, e.g. loads that have to be supported in space
Ababsa, Fakhr-Eddine. "Recalage automatique d'objets 3D de forme libre en utilisant la clinométrie." Evry-Val d'Essonne, 2002. http://www.theses.fr/2002EVRY0019.
Повний текст джерела3D free form object recognition problem is one or the most difficult problems in computer vision. We were interested in this thesis to the particular problem of automatic recovering or such objects in the both cases of the monocular vision associated to a non structured light and active stereovision. Our goal is to demonstrate that the use of the clinometry of the free form object, under some conditions, is sufficient to achieve an accurate and automatic recovering system. Thus, we have elaborated two approaches : The first one, named photoclinometry, exploit only one luminance image of the object to extract a photometric (non geometric) projective invariant which is used to perform matching between regions of the object image and those of the model. We propose an original method based on what we called "photometric aspects" to construct a discriminative data base of the 3D object model. Otherwise, to achieve the image/model matching, we have used the prediction/verification paradigm. The matched primitives are the exploited by the orthogonal iteration (OI) algorithm to compute the rigid transformation undergone by object. The second approach, called "clinometry approach", uses 3D points scanned from the visible surface of the object by an active stereovision sensor (a CDD camera + laser grid projector) which we conceived. From these 3D points, it constructs a local geometric invariant which allow to identify, from a model indexing table, the region of the object (patch) thus rebuilt. Indexing allows to match features extracted from the object model with features extracted from the sensed object wherever it may be within the workspace. The 3D recovery process is formulated differently because in this case use 3D/3D matching. Both elaborated approaches are tested on synthetic images for the first one and realistic images for the second one. We have evaluated the performances of each of the two methods and have given their limits of use. Finally, we tried to lead a critical survey on the implemented methods in order to expose perspectives and improvements to develop in the future
Da, Tran Kai Frank. "L'interpolation de formes." Phd thesis, Université de Nice Sophia-Antipolis, 2002. http://tel.archives-ouvertes.fr/tel-00832486.
Повний текст джерелаDelame, Thomas. "Les squelettes : structures d'interaction directe et intuitive avec des formes 3D." Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS013/document.
Повний текст джерелаThe interactions in shape creation graphic applications are far from natural. The user tends to avoid as much as possible such applications and prefer to sketch or model his/her shape.To bridge this widening gap between computer and the general public, we focus on skeletons. They are intuitive shape representation models that we propose to use as direct and intuitive interaction structures.All skeletons suffer from very low quality as shape representation models, concerning the geometry of the shape they capture, the quantity of skeletal noise they contain or the lack of useful organization of their elements. Moreover, some functionalities that must be granted to skeletons are only partially solved. Those solutions make use of additional data computed thanks to the shape during the skeletonization. Thus, when the skeleton is modified by an interaction, we cannot update those data to make use of such functionalities.Thanks to a practical observation of skeletons, we built a set of algorithmic solutions to those problems.We make an optimal use of skeleton data to visualize the shape described by a skeleton, to remove skeletal noise and to structure skeleton elements. With our methods, we build the meso-skeleton, a hierarchical structure that captures and controls all characteristic parts of a shape.The meso-skeleton is adapted to be used as a direct and intuitive interaction structure, which allows us to bridge the gap aforementioned. Also, our work can lead to further researches to enhance skeletonization techniques and thus produce skeletons that are good quality shape representation models
Limkhaitir, Mohamed Mahmoud. "Modélisation des formes volumiques à partir d'images tomographiques 3D : application à la Caractérisation de l'espace poral du sol." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066556.
Повний текст джерелаIn this thesis we present a primary representation for complex 3D volume shape. We de fine a 3D volume shape by a set of voxels derived from a computed tomography volume image. In a theoretical point of view, this set of voxels defi nes its indicatrix function. The basic idea is to look for a compact, stable and robust piece wise analytic approximation of the shape which conserves its topological and geometrical properties. We propose to describe a volume shape by a minimal number of balls included within the shape and recovering the shape skeleton. We show that it is equivalent to find out a (fi nite) minimal set of "maximal balls" recovering the skeleton. In the case where the absolute values of the principal curvatures of the shape envelope are bounded above we prove that such a finite set does exist. Indeed, our new shape representation provides an optimal description of the shape cavities. We propose an algorithm based on Delaunay 3D triangulation to compute the MISS of a volume shape described by a set of voxels. Afterwards, this representation can be used to approximate the shape using more sophisticated primitives like cylinders, cones, generalized cylinders. We propose algorithms to provide optimal cylinders and cones from ball network. The final result is an intrinsic and robust description of the initial shape using both balls, cylinders, cones. This scheme can be extended by using also curved cylinders and curved cones. Finally, we apply our algorithm to 3D volume Computed Tomography soil data in order to provide intrinsic and robust geometrical description of pore space to be used for biological dynamics simulation and modeling
Dumas, Jérémie. "Synthèse de formes contrôlable pour la fabrication digitale." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0008/document.
Повний текст джерелаThe main goal of this thesis is to propose methods to synthesize shapes in a controllable manner, with the purpose of being fabricated. As 3D printers grow more accessible than ever, modeling software must now take into account fabrication constraints posed by additive manufacturing technologies. Consequently, efficient algorithms need to be devised to model the complex shapes that can be created through 3D printing. We develop algorithms for by-example shape synthesis that consider the physical behavior of the structure to fabricate. All the contributions of this thesis focus on the problem of generating complex shapes that follow geometric constraints and structural objectives. In a first time, we focus on dealing with fabrication constraints, and propose a method for synthesizing efficient support structures that are well-suited for filament printers. In a second time, we take into account appearance control, and develop new by-example synthesis methods that mixes in a meaningful manner criteria on the appearance of the synthesized shapes, and constraints on their mechanical behavior. Finally, we present a highly scalable method to control the elastic properties of printed structures. We draw inspiration from procedural texture synthesis methods, and propose an efficient algorithm to synthesize printable microstructures with controlled elastic properties
Willaume, Pierre. "Modélisation de formes 3D par les graphes pour leur reconnaissance : application à la vision 3D en robotique dans des tâches de "Pick-and-Place"." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAD041/document.
Повний текст джерелаThe aim of this thesis is to design an automatic system involving one or several cameras capable of detecting in three dimensions a set of abjects placed in a bin. To do this, we must model, recognize and locate shapes in an image. First, we propose a solution to optimize the camera calibration system. This is an essential task for the retrieval of quantitative information about the captured images. However, the current methods require specific skills in image processing, which are not always available in industry. We propose to automate and optimize the calibration system by eliminating the selection of images by the operator. Second, we propose to improve the detection systems for thin and featureless abjects. Finally, we propose to adapt evolutionary algorithms to optimize search times
Mahmoudi, Saïd. "Indexation de formes planes : application à la reconnaissance multi-vues de modèles 3D." Lille 1, 2003. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2003/50376-2003-291.pdf.
Повний текст джерелаGemmerlé, Didier. "Contributions à la modélisation automatique d'objets polyédriques 3D construction du modèle à partir de groupements perceptuels." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL076N.
Повний текст джерелаLescoat, Thibault. "Geometric operators for 3D modeling using dictionary-based shape representations." Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAT005.
Повний текст джерелаIn this thesis, we study high-level 3D shape representations and developed the algorithm primitives necessary to manipulate shapes represented as a composition of several parts. We first review existing representations, starting with the usual low-level ones and then expanding on a high-level family of shape representations, based on dictionaries. Notably, we focus on representing shapes via a discrete composition of atoms from a dictionary of parts.We observe that there was no method to smoothly blend non-overlapping atoms while still looking plausible. Indeed, most methods either required overlapping parts or do not preserve large-scale details. Moreover, very few methods guaranteed the exact preservation of the input, which is very important when dealing with artist-authored meshes to avoid destroying the artist's work. We address this challenge by proposing a composition operator that is guaranteed to exactly keep the input while also propagating large-scale details.To improve the speed of our composition operator and allow interactive edition, we propose to simplify the input parts prior to completing them. This allow us to interactively previsualize the composition of large meshes. For this, we introduce a method to simplify a detailed mesh to a coarse one by preserving the large details. While more constrained than related approaches that do not produce a mesh, our method still yields faithful outputs
Moslah, Oussama. "Vers la modélisation grand échelle d'environnements urbains à partir d'images." Phd thesis, Université de Cergy Pontoise, 2011. http://tel.archives-ouvertes.fr/tel-00661101.
Повний текст джерелаFernandez-Abrevaya, Victoria. "Apprentissage à grande échelle de modèles de formes et de mouvements pour le visage 3D." Electronic Thesis or Diss., Université Grenoble Alpes, 2020. https://theses.hal.science/tel-03151303.
Повний текст джерелаData-driven models of the 3D face are a promising direction for capturing the subtle complexities of the human face, and a central component to numerous applications thanks to their ability to simplify complex tasks. Most data-driven approaches to date were built from either a relatively limited number of samples or by synthetic data augmentation, mainly because of the difficulty in obtaining large-scale and accurate 3D scans of the face. Yet, there is a substantial amount of information that can be gathered when considering publicly available sources that have been captured over the last decade, whose combination can potentially bring forward more powerful models.This thesis proposes novel methods for building data-driven models of the 3D face geometry, and investigates whether improved performances can be obtained by learning from large and varied datasets of 3D facial scans. In order to make efficient use of a large number of training samples we develop novel deep learning techniques designed to effectively handle three-dimensional face data. We focus on several aspects that influence the geometry of the face: its shape components including fine details, its motion components such as expression, and the interaction between these two subspaces.We develop in particular two approaches for building generative models that decouple the latent space according to natural sources of variation, e.g.identity and expression. The first approach considers a novel deep autoencoder architecture that allows to learn a multilinear model without requiring the training data to be assembled as a complete tensor. We next propose a novel non-linear model based on adversarial training that further improves the decoupling capacity. This is enabled by a new 3D-2D architecture combining a 3D generator with a 2D discriminator, where both domains are bridged by a geometry mapping layer.As a necessary prerequisite for building data-driven models, we also address the problem of registering a large number of 3D facial scans in motion. We propose an approach that can efficiently and automatically handle a variety of sequences while making minimal assumptions on the input data. This is achieved by the use of a spatiotemporal model as well as a regression-based initialization, and we show that we can obtain accurate registrations in an efficient and scalable manner.Finally, we address the problem of recovering surface normals from natural images, with the goal of enriching existing coarse 3D reconstructions. We propose a method that can leverage all available image and normal data, whether paired or not, thanks to a new cross-modal learning architecture. Core to our approach is a novel module that we call deactivable skip connections, which allows to transfer the local details from the image to the output surface without hurting the performance when autoencoding modalities, achieving state-of-the-art results for the task
Trujillo, Romero Felipe de Jesús. "Modélisation et reconnaissance active d'objets 3D de forme libre par vision en robotique." Phd thesis, Toulouse, INPT, 2008. http://oatao.univ-toulouse.fr/8806/1/trujillo.pdf.
Повний текст джерелаTrujillo-Romero, Felipe De Jesus. "Modélisation et reconnaissance active d'objets 3D de forme libre par vision en robotique." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2008. http://tel.archives-ouvertes.fr/tel-00842693.
Повний текст джерелаArbaret, Laurent. "Orientation préférentielle de forme dans les magmas : modélisation analogique 3D en cisaillement simple." Clermont-Ferrand 2, 1995. http://www.theses.fr/1995CLF21732.
Повний текст джерелаHajri, Souhail. "Modélisation des surfaces rocheuses naturelles à partir d'une scannerisation laser 3D et extraction automatique de formes caractéristiques : applications aux spéléothèmes et surfaces géologiques." Grenoble, 2010. http://www.theses.fr/2010CHAMS039.
Повний текст джерелаThe research work presented in this dissertation concems 3d image processing. We are interested in the automation's tasks of the extraction and the characterization of reliefs fomms in the naturel environment from 3D point clouds acquired by LIDAR. Once thèse data are reconstructed as triangular meshes or TIN models (Triangular Irregular Networks), we are particularly interest in the 3D TIN model segmentation that is one of the essentiel stops of the pattern recognition process. The goal of segmentation is to décompose the TIN model into homogeneous régions with common characteristics that correspond to significant geological objects. However, the images to be processed are relatively complex (natural fomms), and thus req ui red a priori knowledge. Th us, we have initial ly proposed a method for interactive segmentation based on knowledge of the operator. The method involves manually marking the regions of interest in the models to extract the desired geological fomms. This approach is based on the watershed method. Later, a second segmentation solution, more automated is proposed. This solution is focused on two objects which we know perfectly its discriminating features: planar discontinuities and stalagmites. The identification and characterization process of planes discontinuities is based on the unsupervised clustering algorithm named DBSCAN which can automatically extract parameters related to the discontinuities of rock surfaces: orientation, spacing, roughness. . . The second approach, which aims the automatic identification and characterization, is based on ellipse fitting
Tran, Trung Thien. "Extraction robuste de primitives géométriques 3D dans un nuage de points et alignement basé sur les primitives." Doctoral thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/26744.
Повний текст джерелаIn this research project, we address reverse engineering and quality control problems that play significant roles in industrial manufacturing. Reverse engineering attempts to rebuild a 3D model from the scanned data captured from a object, which is the problem similar to 3D surface reconstruction. Quality control is a process in which the quality of all factors involved in production is monitored and revised. In fact, the above systems currently require significant intervention from experienced users, and are thus still far from being fully automated. Therefore, many challenges still need to be addressed to achieve the desired performance for automated production. The first proposition of this thesis is to extract 3D geometric primitives from point clouds for reverse engineering and surface reconstruction. A complete framework to extract multiple types of primitives from 3D data is proposed. In particular, a novel validation method is also proposed to assess the quality of the extracted primitives. At the end, all primitives present in the point cloud are extracted with their associated data points and descriptive parameters. These results could be used in various applications such as scene and building reconstruction, constructive solid geometry, etc. The second proposition of the thesis is to align two 3D datasets using the extracted geometric primitives, which is introduced as a novel and robust descriptor. The idea of using primitives for alignment is addressed several challenges faced by existing registration methods. This alignment problem is an essential step in 3D modeling, registration and model retrieval. Finally, an automatic method to extract sharp features from 3D data of man-made objects is also proposed. By integrating the extracted sharp features into the alignment framework, it is possible implement automatic assignment of primitive correspondences using attribute relational graph matching. Each primitive is considered as a node of the graph and an attribute relational graph is created to provide a structural and relational description between primitives. We have experimented all the proposed algorithms on different synthetic and real scanned datasets. Our algorithms not only are successful in completing their tasks with good results but also outperform other methods. We believe that the contribution of them could be useful in many applications.
Do, Tien Tho. "Optimisation de forme en forgeage 3D." Phd thesis, École Nationale Supérieure des Mines de Paris, 2006. http://pastel.archives-ouvertes.fr/pastel-00001870.
Повний текст джерелаKemgue, Alain Trésor. "Modélisation des formes volumiques complexes par des volumes quadriques. Application à la représentation de l'espace poral du sol à partir des images tomographiques 3D." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS158.pdf.
Повний текст джерелаMost of the natural shapes have complex volume forms that are usually difficult to model using simple analytical equations. The complexity of the representation is due to the heterogeneity of the physical environment and the variety of phenomena involved. In our study, we are interested by the complex volume shapes structures representation from computed tomographic images. Thanks to the technological advances in Computed Tomography scanners, the image acquisition of complex shapes becomes possible. However, these image data are not directly usable for simulation or modeling purposes. In this thesis, we investigate an approach of modeling of such shapes which consists in making a piecewise approximation of the image data by quadric volumes. We propose to use a split-merge strategy and a region growing algorithm to optimize a function that includes both an approximation error term and a scale factor term that is opposed to it. The input of our algorithms is voxel-based shape description and the result is a set of tangent or disjoint quadric volumes representing the shape in an intrinsic way. We apply our method to represent 3D soil pore space obtained from the Computed Tomography scanners. Within this specific context, we validate our geometrical modeling by performing simulations of water draining and microbial decomposition activities on real data soil sample. This study involves several ecological, agricultural and industrial issues
Moron, Véronique. "Mise en correspondance de données 3D avec un modèle CAO : application à l'inspection automatique." Lyon, INSA, 1996. http://theses.insa-lyon.fr/publication/1996ISAL0131/these.pdf.
Повний текст джерелаThis work deals with the automatic inspection of solid based free-form surfaces, using 3D data produced either by a 3D Range sensor or by a Coordinate Measuring Machine. We first introduce a complete state of the art in the 3D modelisation domain. We select two kinds of surface-based models, the first is an interpolated triangulated model, and the other one is an exact NURBS surfaces based model. For each of them, we state the computation of the point/surface entity distance. We present an automatic and robust (up to 50 % of outlier points) general registration method, capable of registering 3D data with a geometric model in any initial state. We apply this method for different applications, like pattern recognition. But mainly for automatic inspection of complex parts. We state an inspection method that produces an inspection report including numerical results concerning global or local tolerance verification. The other outputs are several types of coloured versions of the model indicating the level of discrepancy between the measured points and the model. Using this colouring scheme, an operator or a robotic system can rapidly identify defective parts or monitor process drift on a production line
Michel, Élie. "Interactive authoring of 3D shapes represented as programs." Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAT027.
Повний текст джерелаAlthough hardware and techniques have considerably improved over the years at handling heavy content, digital 3D creation remains fairly complex, partly because the bottleneck also lies in the cognitive load imposed over the designers. A recent shift to higher-order representation of shapes, encoding them as computer programs that generate their geometry, enables creation pipelines that better manage the cognitive load, but this also comes with its own sources of friction. We study in this thesis new challenges and opportunities introduced by program-based representations of 3D shapes in the context of digital content authoring. We investigate ways for the interaction with the shapes to remain as much as possible in 3D space, rather than operating on abstract symbols in program space. This includes both assisting the creation of the program, by allowing manipulation in 3D space while still ensuring a good generalization upon changes of the free variables of the program, and helping one to tune these variables by enabling direct manipulation of the output of the program. We explore diversity of program-based representations, focusing various paradigms of visual programming interfaces, from the imperative directed acyclic graphs (DAG) to the declarative Wang tiles, through more hybrid approaches. In all cases we study shape programs that evaluate at interactive rate, so that they fit in a creation process, and we push this by studying synergies of program-based representations with real time rendering pipelines.We enable the use of direct manipulation methods on DAG output thanks to automated rewriting rules and a non-linear filtering of differential data. We help the creation of imperative shape programs by turning geometric selection into semantic queries and of declarative programs by proposing an interface-first editing scheme for authoring 3D content in Wang tiles. We extend tiling engines to handle continuous tile parameters and arbitrary slot graphs, and to suggest new tiles to add to the set. We blend shape programs into the visual feedback loop by delegating tile content evaluation to the real-time rendering pipeline or exploiting the program's semantics to drive an impostor-based level-of-details system. Overall, our series of contributions aims at leveraging program-based representations of shapes to make the process of authoring 3D digital scenes more of an artistic act and less of a technical task
Altendorf, Hellen. "Analyse morphologique et modélisation en 3D de systèmes aléatoires de fibres." Phd thesis, École Nationale Supérieure des Mines de Paris, 2011. http://pastel.archives-ouvertes.fr/pastel-00667398.
Повний текст джерелаGhomari, Tewfik. "Contribution à la modélisation 3D volumique de la mise en forme des corps plastiques creux." Reims, 2007. http://www.theses.fr/2007REIMS001.
Повний текст джерелаThe principal objective of this thesis is to develop a software of working of the plastic bodies hollow 3D axisymmetric, with a precise distribution of the thicknesses and a cost of less low calculation. That became possible with the development of a new finite element of axisymmetric solid (baptized SFRQ-Axi) based on the kinematic concept of rotation of a space fiber (Space Fiber Rotation concept). The developed finite element has the advantage of converging quickly for the problems with contact presenting of the flexing areas. The choice of the algorithm of search for contact plays also a part in the fast treatment of the management of the nodes candidates to the contact. A simple algorithm of research local is worked out to test the penetration of the segments “masters” by the “Slavic” nodes. Encountered numerical difficulties to which we had faced, and who are due to the strong not geometrical linearities, material and especially with nonthe linearities of contact. Let us underline also the difficulty in managing the incompressibility of the voluminal or axisymmetric finite elements 3D. Two approaches of implicit calculation and clarifies are treated for an example of feeding-bottle. The results obtained shows the good precision of implicit calculation compared to explicit calculation. The tests of validation of the SFRQ-Axi element with contact on a test of inflection of a circular plate, being rolled up on a rigid torus, shows the good speed of convergence and a better precision of the results thicknesses. The results of the tests of working give also a good distribution thicknesses inside the beach given by the experimental results
Richet, Rémy. "high-resolution 3d stratigraphic modelling of the gresse-en-vercors lower cretaceous carbonate platform (SE france) : from digital outcrop modeling to carbonate sedimentary system characterization." Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10144.
Повний текст джерелаCarbonate platforms are characterized by complex sedimentary and stratigraphic architectures that can be expressed at length scale exceeding single outcrops. This work focuses on the Barremian (Lower Cretaceous) deposits of the Gresse-en-Vercors cliff (southeastern France) that provide a seismic-scale slice though a platform margin - analogous to Middle East reservoirs - ideal to study large scale carbonate platform developments in continuous. The cliffs are 500 m high and extend for 25 km along depositional dip, straddling the transition from shallow water platform to deeper basin. New biostratigraphical data shows that the Vercors platform is mainly Lower Barremian. Four stratigraphic sequences were defined, with two complete platform stages, separated by three drowning events.New high-resolution numerical data (LIDAR point-set and high-resolution georeferenced photos) obtained by helicopter survey, allowed the realization of a 3D high-resolution DEM over the entire outcrops. Integrating the stratigraphic observations and the DEM in gOcad result in a continuous 3D stratigraphic architecture and facies model of the carbonate outcrop that can be used for stratigraphic and sedimentological interpretations. The resulting geological model demonstrates that outcrop numerical data and 3D geological modeling are pertinent tools for improving carbonate outcrop characterization and conceptual models of carbonate platform systems. It allows to establish subtle sedimentary profiles and high resolution facies mosaic along seismic scale platform trend. This approach is particularly critical for the 3D characterization of clinoforms and stratigraphic system tracts in non-cylindrical carbonate systems: for example, apparent low stand wedge or distal onlapping lobes in 2D are in reality prograding high stand systems in 3D
Simon, Loïc. "Procedural reconstruction of buildings : towards large scale automatic 3D modeling of urban environments." Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-00637638.
Повний текст джерелаBouchetob, Ahmed Lazhar Fodhil. "Contribution à la modélisation en 2D et 3D du phénomène de discage." Lille 1, 1994. http://www.theses.fr/1994LIL10198.
Повний текст джерелаKalo, Kassem. "Caractérisation microstructurale et modélisation micromécanique de roches poreuses oolithiques." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0203/document.
Повний текст джерелаThe aim of this work is to study the influence of the microstructure of heterogeneous porous rocks on the behavior at the macroscopic scale. Thus, we characterized the microstructure and micromechanical properties (thanks to nano-indentation tests) of two porous oolitic rocks (Lavoux limestone and iron ore) to calculate their effective mechanical and thermal properties. Oolitic rocks are constituted by an assemblage of porous grains (oolites), pores and inter-granular crystals. Scanning electron microscopy and X-ray 3D Computed Tomography were used to identify the different components of these rocks. Particular attention was given to X-Ray computed tomography since this analytical method allows the characterization of the porous network (size, spatial distribution, and volume fraction), and the shapes of oolites and inter-oolitic crystals. The novelty of this work lies in taking into account the 3D real shape of pores. Hence, we approximated porous oolites by spheres and irregularly shaped pores by ellipsoids. This approximation was performed thanks to the principal component analysis (PCA), which provides the geometrical properties such as length of semi-axes and orientation of resulting ellipsoids. The sphericity of the approximated oolites was calculated and the values close to 1 allowed us to consider oolites as spheres. To verify the approximation in the case of pores, we evaluated the contribution of these irregularly shaped three-dimensional pores to the overall elastic properties. Thus, compliance contribution tensors for 3D irregular pores and their ellipsoidal approximations were calculated using the finite element method (FEM). These tensors were compared and a relative error was estimated to evaluate the accuracy of the approximation. This error produces a maximum discrepancy of 4.5% between the two solutions for pores and ellipsoids which verifies the proposed approximation procedure based on PCA. The FEM numerical method was verified by comparing the numerical solution for compliance contribution tensors of ellipsoids to the analytical solution based on Eshelby’s theory. The difference between these two solutions does not exceed 3%. The same numerical method was used to calculate thermal resistivity contribution tensors. Calculated compliance and resistivity contribution tensors were used to evaluate effective elastic properties (bulk modulus and shear coefficient) and effective thermal conductivity by considering the two-step Maxwell homogenization scheme. The results showed an important influence of the porosity on effective properties. Finally, the results obtained for irregular pores were compared to those for ellipsoidal ones and they showed a good agreement with a maximum deviation of 4% which verifies once again the approximation of irregularly shaped pores by tri-axial ellipsoids
Parra-Denis, Estelle. "Analyse morphologique 3D de particules de forme complexes: application aux intermétalliques dans les alliages d'aluminium." Phd thesis, Université Jean Monnet - Saint-Etienne, 2007. http://tel.archives-ouvertes.fr/tel-00164990.
Повний текст джерелаLe travail présenté dans la thèse s'articule autour de deux problématiques : mettre en évidence la distribution volumique des particules intermétalliques dans le volume de la tôle, et caractériser leur forme tridimensionnelle complexe au cours du laminage. Ainsi, des échantillons prélevés à différentes étapes du laminage sont observés par micro tomographie aux rayons X (réalisé à l'ESRF). Les images tridimensionnelles obtenues sont segmentées par la méthode de segmentation multi classe. Elle permet d'extraire chaque type de particule de l'alliage. Une base de donnée contenant chaque particule individualisée est créée. Elle permet de reconstruire l'image binaire du matériau et de travailler particule à particule.
La dispersion des particules est mise en évidence par l'étude du graphe des distances et de la covariance. Puis l'analyse de l'érosion linéaire et de la covariance permet de modéliser le matériau par un modèle probabiliste de type schéma Booléen à grains primaires sphériques.
Une batterie de paramètres morphologiques caractérise la forme tridimensionnelle complexe des particules. Une analyse en composantes principales est ensuite réalisée pour synthétiser l'information. Dans l'espace obtenu, les particules sont classées en cinq familles de forme. Enfin, leur évolution au cours du laminage est étudiée.
Tierny, Julien. "Reeb graph based 3D shape modeling and applications." Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2008. http://tel.archives-ouvertes.fr/tel-00838246.
Повний текст джерелаAkgül, Ceyhun Burak. "Descripteurs de forme basés sur la densité de probabilité et apprentissage des similarités pour la recherche d'objets 3D." Paris, ENST, 2007. http://www.theses.fr/2007ENST0026.
Повний текст джерелаContent-based retrieval research aims at developing search engines that would allow users to perform a query by similarity of content. This thesis deals with two fundamentals problems in content-based 3D object retrieval : (1) How to describe a 3D shape to obtain a reliable representative for the subsequent task of similarity search? (2) How to supervise the search process to learn inter-shape similarities for more effective and semantic retrieval? Concerning the first problem, we develop a novel 3D shape description scheme based on probability density of multivariate local surface features. We constructively obtain local characterizations of 3D points and then summarize the resulting local shape information into a global shape descriptor. For probability density estimation, we use the general purpose kernel density estimation methodology, coupled with a fast approximation algorithm: the fast Gauss transform. Experiments that we have conducted on several 3D object databases show that density-based descriptors are very fast to compute and very effective for 3D similarity search. Concerning the second problem, we propose a similarity learning scheme. Our approach relies on combining multiple similarity scores by optimizing a convex regularized version of the empirical ranking risk criterion. This score fusion approach to similarity learning is applicable to a variety of search engine problems. In this work, we demonstrate its effectiveness in 3D object retrieval
Delalondre, Fabien. "Modélisation et étude 3D des phénomènes adiabatiques dans les procédés de mise en forme à grande vitesse." Phd thesis, École Nationale Supérieure des Mines de Paris, 2008. http://tel.archives-ouvertes.fr/tel-00408755/en/.
Повний текст джерелаNogneng, Dorian. "Non-rigid correspondences between surfaces embedded in 3D." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX109/document.
Повний текст джерелаHandling and processing the massive amount of 3D data has become a challenge with countless applications, such as computer-aided design, biomedical computing, interactive games, machine perception, robotics, etc. Geometry Processing is an area of research at the interface between algorithmics, applied mathematics and computer science related to the above applications, that exists since approximately 50 years. It is a large topic of research that includes sub-areas. The problem of shape correspondence (also known as "shape matching") consists in, given a pair of shapes, finding a "good" correspondence between them. For example we may want the correspondence to preserve geodesic distances, or local geometric features.This problem has received a growing interest, in part due to its wide applicability, for example in animation, shape morphing or statistical shape modeling.The functional map framework is a recent tool that has shown many useful properties for shape matching. This approach provides a smooth compact representation of correspondences between shapes, and most constraints over functional maps can be expressed as linear constraints, which allows a least squares formulation of the problem.In this thesis we focus on the problem of shape correspondence, specifically using functional maps. In Chapter 1 we introduce basic notions and notations that will be used throughout the thesis, related to continuous and discrete surfaces, the Laplace-Beltrami operator, the problem of non-rigid shape matching, and the standard functional map computation pipeline.In Chapter 2 we notice that functional maps that are induced by point-to-point maps should satisfy point-wise product preservation constraints. We apply this observation to shape descriptors in order to improve the previous classical constraints on functional maps. This leads to an approach that allows to extract more information from existing constraints and results in better correspondences, particularly when the number of independent descriptors is small.In Chapter 3 we build on the previous remark, but this time in the situation where we already have a functional map that was computed by an existing method. We notice that the point-wise product preservation can also be used to extend the domain over which the given functional map can transfer functions. We show that this allows to improve the accuracy of function transfer.In Chapter 4 we extend the approach proposed in Chapter 3 by noticing that instead of using point-wise function products, the point-wise composition by any fixed operator should also be preserved. We use a neural network that optimizes the approximation of a given function that we want to transfer, as a point-wise function of some basis functions that we already know how to transfer using a given functional map. We then describe how to apply this trained network to the image of the basis functions to construct the image of the function that we want to transfer. We show preliminary results that suggest that this method can lead to significant improvement for function transfer.Finally, in Chapter 5 we mention other topics studied during the thesis, that are unrelated to non-rigid shape matching
De, Luycker Emmanuel. "Simulation et expérimentation en mise en forme de renforts composites 3D interlocks." Phd thesis, Lyon, INSA, 2009. http://oatao.univ-toulouse.fr/18622/1/DeLuycker_18622.pdf.
Повний текст джерелаOesau, Sven. "Modélisation géométrique de scènes intérieures à partir de nuage de points." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4034/document.
Повний текст джерелаGeometric modeling and semantization of indoor scenes from sampled point data is an emerging research topic. Recent advances in acquisition technologies provide highly accurate laser scanners and low-cost handheld RGB-D cameras for real-time acquisition. However, the processing of large data sets is hampered by high amounts of clutter and various defects such as missing data, outliers and anisotropic sampling. This thesis investigates three novel methods for efficient geometric modeling and semantization from unstructured point data: Shape detection, classification and geometric modeling. Chapter 2 introduces two methods for abstracting the input point data with primitive shapes. First, we propose a line extraction method to detect wall segments from a horizontal cross-section of the input point cloud. Second, we introduce a region growing method that progressively detects and reinforces regularities of planar shapes. This method utilizes regularities common to man-made architecture, i.e. coplanarity, parallelism and orthogonality, to reduce complexity and improve data fitting in defect-laden data. Chapter 3 introduces a method based on statistical analysis for separating clutter from structure. We also contribute a supervised machine learning method for object classification based on sets of planar shapes. Chapter 4 introduces a method for 3D geometric modeling of indoor scenes. We first partition the space using primitive shapes detected from permanent structures. An energy formulation is then used to solve an inside/outside labeling of a space partitioning, the latter providing robustness to missing data and outliers
Boui, Marouane. "Détection et suivi de personnes par vision omnidirectionnelle : approche 2D et 3D." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLE009/document.
Повний текст джерелаIn this thesis we will handle the problem of 3D people detection and tracking in omnidirectional images sequences, in order to realize applications allowing3D pose estimation, we investigate the problem of 3D people detection and tracking in omnidirectional images sequences. This requires a stable and accurate monitoring of the person in a real environment. In order to achieve this, we will use a catadioptric camera composed of a spherical mirror and a perspective camera. This type of sensor is commonly used in computer vision and robotics. Its main advantage is its wide field of vision, which allows it to acquire a 360-degree view of the scene with a single sensor and in a single image. However, this kind of sensor generally generates significant distortions in the images, not allowing a direct application of the methods conventionally used in perspective vision. Our thesis contains a description of two monitoring approaches that take into account these distortions. These methods show the progress of our work during these three years, allowing us to move from person detection to the 3Destimation of its pose. The first step of this work consisted in setting up a person detection algorithm in the omnidirectional images. We proposed to extend the conventional approach for human detection in perspective image, based on the Gradient-Oriented Histogram (HOG), in order to adjust it to spherical images. Our approach uses the Riemannian varieties to adapt the gradient calculation for omnidirectional images as well as the spherical gradient for spherical images to generate our omnidirectional image descriptor
Liebelt, Jörg. "Détection de classes d'objets et estimation de leurs poses à partir de modèles 3D synthétiques." Grenoble, 2010. https://theses.hal.science/tel-00553343.
Повний текст джерелаThis dissertation aims at extending object class detection and pose estimation tasks on single 2D images by a 3D model-based approach. The work describes learning, detection and estimation steps adapted to the use of synthetically rendered data with known 3D geometry. Most existing approaches recognize object classes for a particular viewpoint or combine classifiers for a few discrete views. By using existing CAD models and rendering techniques from the domain of computer graphics which are parameterized to reproduce some variations commonly found in real images, we propose instead to build 3D representations of object classes which allow to handle viewpoint changes and intra-class variability. These 3D representations are derived in two different ways : either as an unsupervised filtering process of pose and class discriminant local features on purely synthetic training data, or as a part model which discriminatively learns the object class appearance from an annotated database of real images and builds a generative representation of 3D geometry from a database of synthetic CAD models. During detection, we introduce a 3D voting scheme which reinforces geometric coherence by means of a robust pose estimation, and we propose an alternative probabilistic pose estimation method which evaluates the likelihood of groups of 2D part detections with respect to a full 3D geometry. Both detection methods yield approximate 3D bounding boxes in addition to 2D localizations ; these initializations are subsequently improved by a registration scheme aligning arbitrary 3D models to optical and Synthetic Aperture Radar (SAR) images in order to disambiguate and prune 2D detections and to handle occlusions. The work is evaluated on several standard benchmark datasets and it is shown to achieve state-of-the-art performance for 2D detection in addition to providing 3D pose estimations from single images
Garcia, Dorian. "Mesure de formes et de champs de déplacements tridimensionnels par stéréo-corrélation d'images." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2001. http://tel.archives-ouvertes.fr/tel-00166476.
Повний текст джерелаDans ce contexte, nous avons développé un système de mesure de formes 3D ou de champs de déplacements 3D par stéréovision (en particulier par stéréo-corrélation).
Cette technique permet : (1) la mesure de la forme 3D d'un objet à partir d'une simple paire d'images stéréoscopiques de l'objet, (2) la mesure de champs de déplacements 3D à partir d'au moins 2 paires d'images correspondant à différents instants de déformation de l'objet (en général analyse d'une séquence de paires d'images acquises en cours de déformation).
Les points développés dans la thèse sont : le calibrage fort d'une caméra ou d'un capteur de vision stéréoscopique, la reconstruction 3D par stéréovision (en particulier par stéréo-corrélation), la mesure de champs de déplacements 3D à partir du couplage de la stéréo-corrélation et du suivi de pixels dans une séquence d'images par corrélation. Compte tenu de la finalité métrologique de ces travaux, nous accordons une attention toute particulière à la précision des méthodes mises en oeuvre (qualité du calibrage, qualité de la mise en correspondance des images, corrélation subpixel,...).
Ces travaux ont été appliqués à l'emboutissage de tôles minces (mesure de formes 3D d'emboutis et mesure de champs de déformations à la surface d'emboutis 3D), à la mise en forme de polymères (mesure de champs de déplacements 3D sur des membranes en élastomère soufflées), et à l'étude du comportement mécanique de bétons réfractaires renforcés de fibres métalliques (mesure de champs de déplacements 3D lors d'essais de traction).
Esnault, Noémie. "Production automatique d'interfaces graphiques 3D pour le Web." Phd thesis, Université Rennes 1, 2011. http://tel.archives-ouvertes.fr/tel-00574772.
Повний текст джерелаMadi, Kamel. "Inexact graph matching : application to 2D and 3D Pattern Recognition." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1315/document.
Повний текст джерелаGraphs are powerful mathematical modeling tools used in various fields of computer science, in particular, in Pattern Recognition. Graph matching is the main operation in Pattern Recognition using graph-based approach. Finding solutions to the problem of graph matching that ensure optimality in terms of accuracy and time complexity is a difficult research challenge and a topical issue. In this thesis, we investigate the resolution of this problem in two fields: 2D and 3D Pattern Recognition. Firstly, we address the problem of geometric graphs matching and its applications on 2D Pattern Recognition. Kite (archaeological structures) recognition in satellite images is the main application considered in this first part. We present a complete graph based framework for Kite recognition on satellite images. We propose mainly two contributions. The first one is an automatic process transforming Kites from real images into graphs and a process of generating randomly synthetic Kite graphs. This allowing to construct a benchmark of Kite graphs (real and synthetic) structured in different level of deformations. The second contribution in this part, is the proposition of a new graph similarity measure adapted to geometric graphs and consequently for Kite graphs. The proposed approach combines graph invariants with a geometric graph edit distance computation. Secondly, we address the problem of deformable 3D objects recognition, represented by graphs, i.e., triangular tessellations. We propose a new decomposition of triangular tessellations into a set of substructures that we call triangle-stars. Based on this new decomposition, we propose a new algorithm of graph matching to measure the distance between triangular tessellations. The proposed algorithm offers a better measure by assuring a minimum number of triangle-stars covering a larger neighbourhood, and uses a set of descriptors which are invariant or at least oblivious under most common deformations. Finally, we propose a more general graph matching approach founded on a new formalization based on the stable marriage problem. The proposed approach is optimal in term of execution time, i.e. the time complexity is quadratic O(n2) and flexible in term of applicability (2D and 3D). The analyze of the time complexity of the proposed algorithms and the extensive experiments conducted on Kite graph data sets (real and synthetic) and standard data sets (2D and 3D) attest the effectiveness, the high performance and accuracy of the proposed approaches and show that the proposed approaches are extensible and quite general
Hlioui, Sami. "Étude d'une machine synchrone à double excitation : contribution à la mise en place d'une plate-forme de logiciels en vue d'un dimensionnement optimal." Besançon, 2008. http://www.theses.fr/2008BESA2030.
Повний текст джерелаThe work presented in this thesis is a contribution to the optimal design of a non conventional machine: Hybrid Excitation Synchronous machine (HESM) and was conducted between the SET laboratory of the UTBM and the SATIE laboratory of the ENS Cachan. The HESM has two excitation sources: one with permanent magnets in focusing configuration and a wound excitation located in the stator. Excitation coils are used to control the air gap magnetic flux generated by the permanent magnets in order either to reinforce it or weaken it. Firstly, 3D finite elements analysis was performed in order to study the impact of the main machine’s parameters on its capability of excitation flux controlling. Secondly, equivalent magnet circuit model has been established. 3D flux paths, leakage flux and saturation phenomena were taken into account. Finally, theses models were used in an optimal design process by using an evolutionary algorithm (NSGA-II) in order to optimize the studied structure for a given specification sheet