Agrandissement adapté des GOP (Group Of Pictures) en vidéo

Cet article traite de l'agrandissement de séquences vidéo dans le but de diminuer les besoins en capacités de stockage et en débits de transmission. Nous définissons un procédé permettant d'agrandir, en résolution spatiale, les images d'une séquence qui peut ensuite être stockée sous forme de "petit format". Dans un premier temps, nous traitons l'agrandissement d'images par induction, une méthode de régularisation développée pour les images fixes que nous étendons à un facteur agrandissement quelconque. Ensuite, nous expliquons comment les vecteurs de mouvement et les images d'erreurs obtenus par un algorithme de Block-matching sont utilisés avec l'induction pour réaliser un agrandissement de séquences vidéo de qualité

A hierarchical approach with triangulated surfaces for 3D data segmentation

This article presents a new algorithm for segmenting three-dimensional images . It is based on a dynamic triangulated surface an d on a pyramidal representation . The triangulated surface, which follows a physical modelization and which can as well modify its geometry as its topology, segments images into their components by altering its shape according to internal and externa l constraints . In order to speed up the whole process, an algorithm of pyramid building with any reduction factor allows us t o transform the image into a set of images with progressive resolutions . This organization into a hierarchy, combined with a model that can adapt its mesh refinement to the resolution of the workspace, authorizes a fast estimation of the general forms included i n the image. After that, the model searches for finer and finer details while relying successively on the different levels of the pyramid.Ce travail présente un algorithme de segmentation d'images tridimensionnelles par utilisation de surfaces triangulées et de pyramides. Une triangulation de surface dynamique, dotée d'une modélisation physique et capable de changer sa topologie, va, en se déformant suivant certaines contraintes, segmenter l'image en ses constituants. Afin d'accélérer le processus, un algorithme de construction de pyramide de facteur de réduction quelconque permet de transformer l'image en un ensemble d'images de résolution progressive. Cette hiérarchisation, couplée à un modèle capable d'adapter la précision de sa maille à la résolution de son espace de travail, permet d'estimer très rapidement les formes générales contenues dans une image. Une fois ceci fait, le modèle recherche les détails de plus en plus petits en s'appuyant successivement sur les différents niveaux de la pyramide

Binary image decomposition applied to a submarine sweeping pattern problem

This paper describes geometrical methods of binary image decompositton . These images are characterized by a complex architecture and the proposcd method uses a graph environnent to connect elementary structures . The application concerns the elaboration of the trajectory of a mining system for the industrial recovery of nodules . Différent sweeping patterns are proposed in illustrations .Méthodes géométriques de décomposition d'images binaires d'architecture complexe. La décomposition est effectuée à l'aide de structures dans un environnement de graphe d'interprétatio

Architecture of discrete binary images geometrical tools

This paper deals with the presentation of geometric methods used to manipulate discrete binary images, in the aim to perform image understanding . This discussion is based on the use of two methods for representation of an image : by contour and by region . We shah discuss about filtering and methods related to the analysis of the global shape : decomposition and partitionning . We shah notice that shape analysis currently used decomposition processes into simpler entities, completed by a relational graph between the resulting primitives . We will present such a method based on the medial axis transform . This study is justified by a problem of treatment of submarine maps. To solve it, several of the presented methods have been used.On traite les 2 modes de représentation utilisés pour une image, à savoir la représentation par contour et la représentation par région. Procédé de filtrage, de description ou de décomposition de formes en vue d'une interprétation locale ou globale des objets représenté

Stochastic Edge Detection Based on Discrete Segments

We present an original edge detector which provides a binary contour element map by looking for significant discontinuities along discrete segments which are computed in the image. The size and the direction of those segments are chosen randomly and thus, discontinuities may be evaluated with many different resolutions. In order to extract a potential discontinuity within each segment, we propose an adaptive criterion which only takes into account the pixels on this segment. This process is iterated many times, allowing to find weak edges in short segments and strong edges in longer segments, according to the criterion. Some results on different kinds of images are given. Key Words Image Segmentation, Edge Detector, Stochastic Process, Random Segments. E.Mail [email protected] - Tel 76 54 95 89 - FAX 76 54 95 49 y E.Mail [email protected] 1 Introduction In order to study and understand the content of an image, a process called segmentation has to extract..

XPMaps and Topological Segmentation - a Unified Approach to Finite Topologies in the Plane

Finite topological spaces ae now widely recognized as a valuable tool of image analysis. However, their practical application is complicated because there are so many different approaches. We show that there are close relationships between those approaches which motivate the introduction of XPMaps as a concept that subsumes the important characteristics of the other approaches. The notion of topological segmentations then extends tftis concept to a particula class of labelings of XPMaps. We show that tfte new notions lead to significant simplifications from both a theoretical and practical viewpoint

Receptive fields within the Combinatorial Pyramid framework

A hierarchical structure is a stack of successively reduced image representations. Each basic element of a hierarchical structure is the father of a set of elements in the level below. The transitive closure of this father-child relationship associates to each element of the hierarchy a set of basic elements in the base level image representation. Such a set, called a receptive field, defines the embedding of one element of the hierarchy on the original image. Using the father-child relationship, global properties of a receptive field may be computed in O(log(m)) parallel processing steps where m is the diameter of the receptive field. Combinatorial pyramids are defined as a stack of successively reduced combinatorial maps, each combinatorial map being defined by two permutations acting on a set of half edges named darts. The basic element of a combinatorial pyramid is thus the dart. This paper defines the receptive field of each dart within a combinatorial pyramid and study the main properties of these sets