WorldCat Identities

Tierny, Julien 1982-

Overview
Works: 12 works in 31 publications in 2 languages and 312 library holdings
Genres: Conference papers and proceedings 
Roles: Author, Opponent, Editor, htt, dgs, Other
Classifications: TK7882.I6, 001.4226028566
Publication Timeline
.
Most widely held works by Julien Tierny
Topological data analysis for scientific visualization by Julien Tierny( )

13 editions published between 2017 and 2019 in English and held by 275 WorldCat member libraries worldwide

Combining theoretical and practical aspects of topology, this book delivers a comprehensive and self-contained introduction to topological methods for the analysis and visualization of scientific data. Theoretical concepts are presented in a thorough but intuitive manner, with many high-quality color illustrations. Key algorithms for the computation and simplification of topological data representations are described in details, and their application is carefully illustrated in a chapter dedicated to concrete use cases. With its fine balance between theory and practice, "Topological Data Analysis for Scientific Visualization" constitutes an appealing introduction to the increasingly important topic of topological data analysis, for lecturers, students and researchers
Topological Methods in Data Analysis and Visualization : Theory, Algorithms, and Applications by Valerio Pascucci( )

5 editions published between 2010 and 2011 in English and held by 22 WorldCat member libraries worldwide

Annotation
Topological methods in data analysis and visualization : theory, algorithms, and applications by Peer-Timo Bremer( )

2 editions published in 2011 in English and held by 4 WorldCat member libraries worldwide

Topology-based methods are of increasing importance in the analysis and visualization of datasets from a wide variety of scientific domains such as biology, physics, engineering, and medicine. Current challenges of topology-based techniques include the management of time-dependent data, the representation large and complex datasets, the characterization of noise and uncertainty, the effective integration of numerical methods with robust combinatorial algorithms, etc. While there is an increasing number of high-quality publications in this field, many fundamental questions remain unsolved. New focused efforts are needed in a variety of techniques ranging from the theoretical foundations of topological models, algorithmic issues related to the representation power of computer-based implementations as well as their computational efficiency, user interfaces for presentation of quantitative topological information, and the development of new techniques for systematic mapping of science problems in topological constructs that can be solved computationally. The editors have brought together the most prominent and best recognized researchers in the field of topology-based data analysis and visualization for a joint discussion and scientific exchange of the latest results in the field. The 2009 "TopoInVis" workshop in Snowbird, Utah, follows the two successful workshops in 2005 (Budmerice, Slovakia) and 2007 (Leipzig, Germany)
Reeb graph based 3D shape modeling and applications by Julien Tierny( Book )

2 editions published in 2008 in English and held by 2 WorldCat member libraries worldwide

Avec le développement récent des technologies 3D, les formes 3D sont devenues un type de données multimedia interactives de première importance. Leur représentation la plus courante, le maillage de polygones, souffre cependant de grande variabilité face à des transformations canoniques préservant la forme. Il est donc nécessaire de concevoir des techniques de modélisation intrinsèque de forme. Dans cette thèse, nous explorons la modélisation topologique par l'étude de structures basées sur les graphes de Reeb. En particulier, nous introduisons une nouvelle abstraction de forme, appelée squelette topologique avancé, qui permet non seulement l'étude de l'évolution topologique des lignes de niveau de fonctions de Morse mais aussi l'étude de leur évolution géométrique. Nous démontrons l'utilité de cette représentation intrinsèque de forme dans trois problèmes de recherche liés à l'Informatique Graphique et à la Vision par Ordinateur.Tout d'abord, nous introduisons la notion de calcul géométrique sur les graphes de Reeb pour le calcul automatique et stable de squelettes de contrôle pour la manipulation interactive de forme. Ensuite, en introduisant les notions de cartes de Reeb et de motifs de Reeb, nous proposons une nouvelle méthode pour l'estimation de similarité partielle entre formes 3D. Nous montrons que cette approche dépasse les méthodes participant au concours international de reconnaissance de forme 2007 (SHREC 2007) par un gain de 14%. Enfin, nous présentons deux techniques permettant de fournir une décomposition fonctionnelle d'une forme 3D, à la fois en considérant des heuristiques issues de la théorie de la perception humaine et des données 3D variant dans le temps
Visualisation de champs scalaires guidée par la topologie by Leo Allemand Giorgis( )

1 edition published in 2016 in French and held by 2 WorldCat member libraries worldwide

Les points critiques d'une fonction scalaire (minima, points col et maxima) sont des caractéristiques importantes permettant de décrire de gros ensembles de données, comme par exemple les données topographiques. L'acquisition de ces données introduit souvent du bruit sur les valeurs. Un grand nombre de points critiques sont créés par le bruit, il est donc important de supprimer ces points critiques pour faire une bonne analyse de ces données. Le complexe de Morse-Smale est un objet mathématique qui est étudié dans le domaine de la Visualisation Scientifique car il permet de simplifier des fonctions scalaires tout en gardant les points critiques les plus importants de la fonction étudiée, ainsi que les liens entre ces points critiques. Nous proposons dans cette thèse une méthode permettant de construire une fonction qui correspond à un complexe de Morse-Smale d'une fonction définie sur R^2 après suppression de paires de points critiques dans celui-ci.Tout d'abord, nous proposons une méthode qui définit une surface interpolant des valeurs de fonction aux points d'une grille de façon monotone, c'est-à-dire en ne créant pas de point critique. Cette surface est composée d'un ensemble de patchs de Bézier triangulaires cubiques assemblés de telle sorte que la surface soit globalement C^1. Nous donnons des conditionssuffisantes sur les valeurs d fonction et les valeurs de dérivées partielles aux points de la grille afin que la surface soit croissante dans la direction (x+y). Il n'est pas évident de créer des valeurs de dérivées partielles en chaque point de la grille vérifiant ces conditions. C'est pourquoi nous introduisons deux algorithmes : le premier permet de modifier des valeurs de dérivées partielles données en entrée afin que celles-ci vérifient les conditions et le second calcule des valeurs de dérivées partielles à partir des valeurs de fonctions aux points de la grille.Ensuite, nous décrivons une méthode de reconstruction de champs scalaires à partir de complexes de Morse-Smale simplifiés. Pour cela, nous commençons par approximer les 1-cellules (les liens entre les points critiques dans le complexe de Morse-Smale, ceux-ci sont décrits par des polylignes) par des courbes composées de courbes de Bézier cubiques. Nous décrivons ensuite comment notre interpolation monotone de valeurs aux points d'une grille est utilisée pour construire des surfaces monotones interpolant les courbes construites précédemment. De plus, nous montrons que la fonction reconstruite contient tout les points critiques du complexe de Morse-Smale simplifié et n'en contient aucun autre
Topological Methods in Data Analysis and Visualization by Valerio Pascucci( Book )

2 editions published between 2010 and 2011 in English and held by 2 WorldCat member libraries worldwide

Topology-based methods are of increasing importance in the analysis and visualization of datasets from a wide variety of scientific domains such as biology, physics, engineering, and medicine. Current challenges of topology-based techniques include the management of time-dependent data, the representation of large and complex datasets, the characterization of noise and uncertainty, the effective integration of numerical methods with robust combinatorial algorithms, etc. . The editors have brought together the most prominent and best recognized researchers in the field of topology-based data an
Séquences de maillages : classification et méthodes de segmentation by Romain Arcila( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

Mesh sequences are becoming a common tool in computer graphics as can be seen in video games or medical imaging. As a consequence, mesh sequences generation's methods have been developed. Sequences can be created using a modeler or by multicameras acquisition. These methods can generate sequences which have different properties. Moreover, different applications using mesh sequences have been proposed such as compression or pose transfer. Most of these applications require to compute a segmentation as a pre-processing step. This thesis deals with mesh sequence segmentation into rigid components. First, we formalize the notion of mesh sequence, and propose a nomenclature, allowing us to design the properties attached to each kind of mesh sequence, and to describe precisely what kind of sequence an algorithm requires as input. Next, we propose a formalization of mesh sequence segmentation by providing different definitions of segmentation.We then present mesh sequences segmentation state of the art. We then propose a first segmentation method, producing a global segmentationand taking as input a stable mesh sequence. This method is based on a region-growing process. Next, we present two segmentation methods, both based on spectral clustering and taking as input an unconstrained mesh sequence. The former method produces a set of global segmentations, while the latter generate either a global segmentation or a timevarying segmentation. We also propose a quantitative segmentation evaluation system. Finally, we provide future work leads on mesh sequence segmentation
Topology-Based Characterization and Visual Analysis of Feature Evolution in Large-Scale Simulations by Jonas Lukasczyk( Book )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

Une approche basée graphes pour la modélisation et le traitement de nuages de points massifs issus d'acquisitions de LiDARs terrestres by Arnaud Bletterer( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

With the evolution of 3D acquisition devices, point clouds have now become an essential representation of digitized scenes. Recent systems are able to capture several hundreds of millions of points in a single acquisition. As multiple acquisitions are necessary to capture the geometry of large-scale scenes, a historical site for example, we obtain massive point clouds, i.e., composed of billions of points. In this thesis, we are interested in the structuration and manipulation of point clouds from acquisitions generated by terrestrial LiDARs. From the structure of each acquisition, graphs, each representing the local connectivity of the digitized surface, are constructed. Created graphs are then linked together to obtain a global representation of the captured surface. We show that this structure is particularly adapted to the manipulation of the underlying surface of massive point clouds, even on computers with limited memory. Especially, we show that this structure allow to deal with two problems specific to that kind of data. A first one linked to the resampling of point clouds, by generating distributions of good quality in terms of blue noise thanks to a Poisson disk sampling algorithm. Another one connected to the construction of centroidal Voronoi tessellations, allowing to enhance the quality of generated distributions and to reconstruct triangular meshes
Génération de texture par anamorphose pour la décoration d'objets plastiques injectés by Maxime Belperin( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

This work takes part in a global industrial project called IMD3D, which is supported by FUI and aims at decorating 3D plastic objects using Insert Molding technology with an automated process. Our goal is to compute the decoration of 3D virtual objects, using data coming from polymer film characterization and mechanical simulation. My thesis deals with the generation of decoration. Firstly, we want to map the texture onto the mesh, so that the visual rendering would be equivalent to the initial picture. In order to do so, we decided to choose a viewpoint per texture and to favor it. Thus, a specific view-dependent parameterization is defined. Thus, the first goal which is to define the texture mapping with visual constraints is reached. After this step, the inverse distortion of the mesh is performed. The use of a conformal map for this inverse transform allows to respect the physics issues. Therefore we get a planar mesh representing the initial mesh of simulation whose associated textures have also been modified by this transform. The result to be printed on the film can be viewed. Finally, the texture enabling the decoration of the object injected by the process can be generated. This texture combines information from several mapped images. The inner part of the mesh and in the same time the part of the corresponding texture shall be followed in a bilinear way in order to fill the pixel of the generated picture. But during the first tests performed by industries with a colors pattern, a discoloration effect was detected. As a consequence, we thought to take into account this color change to modify the picture and to obtain the expected visual rendering
Segmentation de maillages 3D par l'exemple by Esma Elghoul( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

In this dissertation, we present a new method to segment 3D models into their functional parts. The segmentation is performed by a transfer approach: a semantic-oriented segmentation of an object is calculated using a pre-segmented example model from the same class (chairs, humans, etc.). To this end, we adapted and extended the random walk segmentation method which allowed us to transform our problem into a problem of locating and matching seed faces. Our method consists of four fundamental steps: establishing correspondences between the example and the target model, localizing seeds to initialize regions in the target model, computing the segments and refining their boundaries in the target model. We decomposed our approach in two, taking into account similarity criteria which differ regarding the object type (rigid vs. articulated). The first approach is dedicated to rigid objects (chairs, airplanes, etc.), where the matching is based on rigid transformations to determine the best alignment between the functional parts of the compared objects. The second one focused on articulated objects (humans, quadrupeds, etc.), where coarse topological shape attributes are used in a skeleton-based approach to cover larger pose variations when computing correspondences between functional parts. We show through qualitative and quantitative evaluations that our method improves upon individual segmentation techniques and obtains results that are close to the co-segmentation techniques results with an important calculation time reduction
Topological Methods in Data Analysis and Visualization : Theory, Algorithms, and Applications( )

1 edition published in 2011 in English and held by 0 WorldCat member libraries worldwide

 
moreShow More Titles
fewerShow Fewer Titles
Audience Level
0
Audience Level
1
  Kids General Special  
Audience level: 0.61 (from 0.50 for Topologica ... to 1.00 for Topologica ...)

Topological Methods in Data Analysis and Visualization : Theory, Algorithms, and Applications Topological Methods in Data Analysis and Visualization
Covers
Topological Methods in Data Analysis and Visualization
Languages
English (26)

French (5)