Download or read book Proposition d une m thode de segmentation adaptative bas e sur les indices locaux de l image written by Soltane Schahrazad and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book UNE METHODE DE SEGMENTATION ADAPTATIVE BASEE SUR LES INDICES LOCAUX DE L IMAGE written by SCHAHRAZAD.. SOLTANE and published by . This book was released on 1999 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE PROBLEME DU TRAITEMENT NUMERIQUE DE L'IMAGE EST APPARU IL Y A UNE TRENTAINE D'ANNEES AVEC L'AVENEMENT DES ORDINATEURS. LES CHERCHEURS SE SONT RAPIDEMENT APERCUS DE LA COMPLEXITE DU PROBLEME. EN EFFET, L'IMAGE NUMERIQUE EST UNE MATRICE DE VALEURS D'INTENSITES LUMINEUSES, NOYEE D'INFORMATIONS INUTILES (BRUIT, REDONDANCE,). POUR REMEDIER A CE PROBLEME, LES CHERCHEURS ONT DEVELOPPE DES FILTRES POUR ATTENUER LE BRUIT, DES METHODES D'EXTRACTION DE CONTOURS, AINSI QUE DES METHODES D'EXTRACTION DE REGIONS POUR REDUIRE LA QUANTITE DE DONNEES NECESSAIRE. LE REGROUPEMENT DES CONTOURS ET DES REGIONS EXTRAITES DOIT ABOUTIR A UNE TRANSFORMATION DE L'INFORMATION IMAGE EN OBJETS INTERPRETABLES. C'EST CE QU'ON APPELLE, LA SEGMENTATION. DANS LA CONCEPTION DES ALGORITHMES DE SEGMENTATION CORRESPONDANT A DES APPLICATIONS DONNEES, LE CHOIX DES OPERATEURS ET DES MESURES EST DIFFICILE, IL RESTE LIE AUX APPLICATIONS. L'OPERATEUR IDEAL DOIT ETRE CAPABLE D'EXTRAIRE LES INFORMATIONS PERTINENTES. IL EST CARACTERISE PAR SON EFFET SUR LES DETAILS DE N'IMPORTE QUEL TYPE D'IMAGE (IMAGE A CONTOURS RAPPROCHES, A CONTOURS FLOUS, IMAGE TEXTUREE, FAIBLE RAPPORT SIGNAL SUR BRUIT). LA RECHERCHE MENEE VISE A DEFINIR UNE METHODE GENERALE DE SEGMENTATION D'IMAGES DE MANIERE A POUVOIR FAIRE COOPERER DIVERS OPERATEURS D'EXTRACTIONS DE CONTOURS. LE BUT RECHERCHE ETAIT LA SELECTION ET L'ADAPTATION DE METHODES EXISTANTES EN FONCTION DE LEUR EFFICACITE DANS UN CONTEXTE DETERMINE. CELA A ETE RENDU POSSIBLE GRACE A UNE EVALUATION DE LA DETECTION ET A L'OBSERVATION DE PRESENCE D'INFORMATIONS INDICIAIRES A CHAQUE FOIS QU'UNE METHODE A ETE QUALIFIEE D'ADEQUATE.

Download or read book Image and Video Processing written by and published by . This book was released on 1996 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Int gration et pond ration d indices visuels written by and published by . This book was released on 2004 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les travaux présentés dans ce mémoire ont pour but d'étudier un système de segmentation automatisé en vue d'une application à la recherche d'images de type multimédia dans une base de données. Pour cela, nous avons, dans un premier temps, étudié les principaux algorithmes de segmentation disponibles dans la littérature. Cette étude nous a conduit à analyser la problématique liée à la multiplication des informations utiles à la segmentation. Ainsi, la conception d'un algorithme de segmentation pour images multimédia impose d'intégrer un large panel d'informations telles que les couleurs, les textures, les contours, etc. Toutefois, ces informations présentent des aspects discriminants (au sens de la segmentation), variables en fonction de l'image. Partant de ce constat, nous avons, dans un deuxième temps, étudié des méthodes d'intégration d'informations, susceptibles de répondre à cette problématique. Puis, nous avons proposé un système itératif d'intégration d'indices visuels basé sur une analyse en composantes principales et utilisant un ensemble de matrices d'affinités inter-régions comme données initiales. De nombreux tests nous ont permis de vérifier les capacités d'adaptation et de sélection de notre système en fonction de l'image. Afin d'évaluer notre méthode de segmentation, nous l'avons comparé à d'autres algorithmes en utilisant la mesure d'erreur BCE qui offre la possibilité de comparer les résultats fournis automatiquement avec des segmentations obtenues manuellement. Enfin, la dernière partie de ce mémoire, propose d'utiliser le résultat de segmentation comme une signature propre à chaque image que nous intégrons au sein d'un système de recherche dans une base. L'algorithme de recherche utilise un principe de sélection et de pondération des informations similaire à celui proposé dans la méthode segmentation. Les tests effectués ont permis de présenter des résultats encourageants.

Download or read book Segmentation d images par combinaison adaptative couleur texture et classification de pixels written by Dhouha Attia and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: En segmentation d'images, les informations de couleur et de texture sont très utilisées. Le premier apport de cette thèse se situe au niveau de l'utilisation conjointe de ces deux sources d'informations. Nous proposons alors une méthode de combinaison couleur/texture, adaptative et non paramétrique, qui consiste à combiner un (ou plus) gradient couleur et un (ou plus) gradient texture pour ensuite générer un gradient structurel utilisé comme image de potentiel dans l'algorithme de croissance de régions par LPE. L'originalité de notre méthode réside dans l'étude de la dispersion d'un nuage de point 3D dans l'espace, en utilisant une étude comparative des valeurs propres obtenues par une analyse des composantes principales de la matrice de covariance de ce nuage de points. L'approche de combinaison couleur/texture proposée est d'abord testée sur deux bases d'images, à savoir la base générique d'images couleur de BERKELEY et la base d'images de texture VISTEX. Cette thèse s'inscrivant dans le cadre des projets ViLoc (RFC) et CAPLOC (PREDIT), le deuxième apport de celle-ci se situe au niveau de la caractérisation de l'environnement de réception des signaux GNSS pour améliorer le calcul de la position d'un mobile en milieu urbain. Dans ce cadre, nous proposons d'exclure certains satellites (NLOS dont les signaux sont reçus par réflexion voir totalement bloqués par les obstacles environnants) dans le calcul de la position d'un mobile. Deux approches de caractérisation, basées sur le traitement d'images, sont alors proposées. La première approche consiste à appliquer la méthode de combinaison couleur/texture proposée sur deux bases d'images réelles acquises en mobilité, à l'aide d'une caméra fisheye installée sur le toit du véhicule de laboratoire, suivie d'une classification binaire permettant d'obtenir les deux classes d'intérêt « ciel » (signaux LOS) et « non ciel » (signaux NLOS). Afin de satisfaire la contrainte temps réel exigée par le projet CAPLOC, nous avons proposé une deuxième approche basée sur une simplification de l'image couplée à une classification pixellaire adaptée. Le principe d'exclusion des satellites NLOS permet d'améliorer la précision de la position estimée, mais uniquement lorsque les satellites LOS (dont les signaux sont reçus de manière direct) sont géométriquement bien distribués dans l'espace. Dans le but de prendre en compte cette connaissance relative à la distribution des satellites, et par conséquent, améliorer la précision de localisation, nous avons proposé une nouvelle stratégie pour l'estimation de position, basée sur l'exclusion des satellites NLOS (identifiés par le traitement d'images), conditionnée par l'information DOP, contenue dans les trames GPS.

Download or read book MISE EN OEUVRE D UN SYSTEME ADAPTATIF DE SEGMENTATION D IMAGES written by CHRISTOPHE.. ROSENBERGER and published by . This book was released on 1999 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: LE TRAITEMENT D'IMAGES SUSCITE UN INTERET CROISSANT A MESURE QUE L'IMAGE S'IMPOSE COMME UN SUPPORT ET UNE SOURCE D'INFORMATIONS PRIVILEGIES. LA QUALITE DE L'INTERPRETATION D'UNE IMAGE DEPEND FORTEMENT DE CELLE DE LA SEGMENTATION. MALGRE LA GRANDE DIVERSITE DE METHODES, LES RESULTATS DE SEGMENTATION RESTENT MOYENS ET VARIENT BEAUCOUP EN FONCTION DE LA TECHNIQUE CHOISIE. UNE METHODE DE SEGMENTATION GENERALE ET AUTOMATIQUE EST DIFFICILE A CONCEVOIR ETANT DONNES LES DIFFERENTS TYPES DE REGIONS POUVANT ETRE PRESENTES DANS UNE IMAGE. AFIN DE CONTRIBUER A RESOUDRE CE PROBLEME, NOUS PROPOSONS UN SYSTEME ADAPTATIF DE SEGMENTATION D'IMAGES. APRES UN TRAVAIL DE SYNTHESE PERMETTANT DE REPERTORIER LES DIFFERENTES METHODES DE SEGMENTATION EXISTANTES EN FONCTION DU TYPE D'INFORMATIONS POUR LESQUELLES ELLES SONT PERFORMANTES, UN SYSTEME ORIGINAL DE SEGMENTATION EST PROPOSE. L'ORIGINALITE DE CE SYSTEME RESIDE DANS L'ADAPTATION DES TRAITEMENTS AU CONTEXTE LOCAL DE L'IMAGE AVEC LE MINIMUM DE CONNAISSANCES A PRIORI. IL EST CONSTITUE DE TROIS MODULES DE TRAITEMENT. LE PREMIER MODULE PERMET D'ANALYSER FINEMENT L'IMAGE A DEUX NIVEAUX. LE PREMIER NIVEAU IDENTIFIE D'UNE PART, LE CONTEXTE GLOBAL DE L'IMAGE A TRAITER (IMAGE MAJORITAIREMENT COMPOSEE DE REGIONS UNIFORMES OU TEXTUREES) AFIN D'ADAPTER LA SUITE DES TRAITEMENTS ET, DISTINGUE D'AUTRE PART, LES ZONES TEXTUREES ET UNIFORMES LA COMPOSANT. LE SECOND NIVEAU DU MODULE CONCERNE L'ANALYSE LOCALE DE L'IMAGE A SEGMENTER AFIN DE CARACTERISER CHACUNE DES REGIONS DETECTEES PAR DES ATTRIBUTS CLASSIQUES DE TEXTURES PERTINENTS (OBTENUS PAR ANALYSE STATISTIQUE) ET DES ATTRIBUTS QUE NOUS AVONS DEFINIS. CES PARAMETRES COMPLEMENTAIRES ONT ETE DETERMINES A PARTIR D'UN MODELE DE TEXTURE BASE SUR LA DECOMPOSITION DE WOLD DE LA FONCTION D'AUTOCOVARIANCE. ILS PERMETTENT D'OBTENIR DES INFORMATIONS SUR LE TYPE DE TEXTURE (ALEATOIRE OU DETERMINISTE) ET SUR SA GRANULARITE (GROSSIERE OU FINE). CETTE ANALYSE PLUS FINE D'UNE REGION TEXTUREE PERMET, D'UNE PART, DE FACILITER LE CHOIX DE LA METHODE DE SEGMENTATION APPROPRIEE ET, D'AUTRE PART, D'ADAPTER LA TAILLE DU SUPPORT D'ANALYSE DE LA REGION A SEGMENTER. LE DEUXIEME MODULE DECLENCHE LA METHODE DE SEGMENTATION ADAPTEE AU CONTEXTE LOCAL DE L'IMAGE EN UTILISANT UNE METHODE DE CLASSIFICATION NON SUPERVISEE QUE NOUS AVONS DEVELOPPEE. ENFIN, LE TROISIEME MODULE PERMET DE FUSIONNER SOIT LES RESULTATS DE PLUSIEURS METHODES DE SEGMENTATION D'UNE MEME IMAGE, SOIT LES RESULTATS DE SEGMENTATION DE CHAQUE BANDE DANS LE CAS D'UNE IMAGE MULTI-COMPOSANTES. LA METHODE DE FUSION DEVELOPPEE ADOPTE UNE APPROCHE GENETIQUE EN COMBINANT LES RESULTATS DE SEGMENTATION PONDERES PAR UN CRITERE D'EVALUATION. LE SYSTEME A ETE VALIDE SUR DIFFERENTS TYPES D'IMAGE (SYNTHETIQUES ET REELLES DE TELEDETECTION).

Download or read book Segmentation D images Ultrasonores Bas e Sur Des Statistiques Locales Avec Une S lection Adaptative D chelles written by Qing Yang and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Image segmentation is an important research area in image processing and a large number of different approaches have been developed over the last few decades. The active contour approach is one of the most popular among them. Within this framework, this thesis aims at developing robust algorithms, which can segment images with intensity inhomogeneities. We focus on the study of region-based external energies within the level set framework. We study the use of local image statistics for the design of external energies. Precisely, we address the difficulty of choosing the scale of the spatial window that defines locality. Our main contribution is to propose an adaptive scale for local region-based segmen¬tation methods. We use the Intersection of Confidence Intervals approach to define this pixel-dependent scale for the estimation of local image statistics. The scale is optimal in the sense that it gives the best trade-off between the bias and the variance of a Local Polynomial Approximation of the observed image conditional on the current segmenta¬tion. Additionally, for the segmentation model based on a Bayesian interpretation with two local kernels, we suggest to consider their values separately. Our proposition gives a smoother segmentation with less mis-localisations Chan the original method.Comparative experiments of our method to other local region-based segmentation me¬thods are carried out. The quantitative results, on simulated ultrasound B-mode images, show that the proposed scale selection strategy gives a robust solution to the intensity inhomogeneity artifact of this imaging modality. More general experiments on real images also demonstrate the usefulness of our approach.

Download or read book Anisotropic Mesh Adaptation for Image Segmentation Based on Partial Differential Equations written by Karrar Kadhim Abbas and published by . This book was released on 2020 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the resolution of digital images increases significantly, the processing of images becomes more challenging in terms of accuracy and efficiency. In this dissertation, we consider image segmentation by solving a partial differential equation (PDE) model based on the Mumford-Shah functional. We first, develop a new anisotropic mesh adaptation (AMA) framework to improve segmentation efficiency and accuracy. In the AMA framework, we incorporate an anisotropic mesh adaptation for image representation and a nite element method for solving the PDE model. Comparing to traditional algorithms solved by the finnite difference method, our AMA framework provides faster and better results without the need for re-sizing the images to lower quality. We also extend the algorithm to segment images with multiple regions. We also improve the well-known Chan-Vese model by developing a locally enhanced Chan-Vese (LECV) model. Our LECV model incorporates a newly define signed pressure force (SPF) function, which is built upon the local image information. The SPF function helps to attract the contour curve to the object boundaries for images with inhomogeneous intensities. The proposed LECV model, together with the AMA segmentation framework can successfully segment the image with or without inhomogeneous intensities. While most other segmentation methods only work on low-resolution images, our LECV model is successfully applied to high-resolution images, with improved efficiency and accuracy.

Download or read book Multispectral Image Analysis Using the Object Oriented Paradigm written by Kumar Navulur and published by CRC Press. This book was released on 2006-12-05 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bringing a fresh new perspective to remote sensing, object-based image analysis is a paradigm shift from the traditional pixel-based approach. Featuring various practical examples to provide understanding of this new modus operandi, Multispectral Image Analysis Using the Object-Oriented Paradigm reviews the current image analysis methods and demonstrates advantages to improve information extraction from imagery. This reference describes traditional image analysis techniques, introduces object-oriented technology, and discusses the benefits of object-based versus pixel-based classification. It examines the creation of object primitives using image segmentation approaches and the use of various techniques for object classification. The author covers image enhancement methods, how to use ancillary data to constrain image segmentation, and concepts of semantic grouping of objects. He concludes by addressing accuracy assessment approaches. The accompanying downloadable resources present sample data that enable the use of different approaches to problem solving. Integrating remote sensing techniques and GIS analysis, Multispectral Image Analysis Using the Object-Oriented Paradigm distills new tools to extract information from remotely sensed data.

Download or read book Information Theory Tools for Image Processing written by Miquel Feixas and published by Morgan & Claypool Publishers. This book was released on 2014-03-01 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information Theory (IT) tools, widely used in many scientific fields such as engineering, physics, genetics, neuroscience, and many others, are also useful transversal tools in image processing. In this book, we present the basic concepts of IT and how they have been used in the image processing areas of registration, segmentation, video processing, and computational aesthetics. Some of the approaches presented, such as the application of mutual information to registration, are the state of the art in the field. All techniques presented in this book have been previously published in peer-reviewed conference proceedings or international journals. We have stressed here their common aspects, and presented them in an unified way, so to make clear to the reader which problems IT tools can help to solve, which specific tools to use, and how to apply them. The IT basics are presented so as to be self-contained in the book. The intended audiences are students and practitioners of image processing and related areas such as computer graphics and visualization. In addition, students and practitioners of IT will be interested in knowing about these applications.

Download or read book Information Theory in Computer Vision and Pattern Recognition written by Francisco Escolano Ruiz and published by Springer Science & Business Media. This book was released on 2009-07-14 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information theory has proved to be effective for solving many computer vision and pattern recognition (CVPR) problems (such as image matching, clustering and segmentation, saliency detection, feature selection, optimal classifier design and many others). Nowadays, researchers are widely bringing information theory elements to the CVPR arena. Among these elements there are measures (entropy, mutual information...), principles (maximum entropy, minimax entropy...) and theories (rate distortion theory, method of types...). This book explores and introduces the latter elements through an incremental complexity approach at the same time where CVPR problems are formulated and the most representative algorithms are presented. Interesting connections between information theory principles when applied to different problems are highlighted, seeking a comprehensive research roadmap. The result is a novel tool both for CVPR and machine learning researchers, and contributes to a cross-fertilization of both areas.

Download or read book Applied Informatics written by M. H. Hamza and published by . This book was released on 1988 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Intelligent Systems written by S.G. Tzafestas and published by Springer Science & Business Media. This book was released on 2001-11-30 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intelligent Systems involve a large class of systems which posses human-like capabilities such as learning, observation, perception, interpretation, reasoning under uncertainty, planning in known and unknown environments, decision making, and control action. The field of intelligent systems is actually a new interdisciplinary field which is the outcome of the interaction, cooperation and synergetic merging of classical fields such as system theory, control theory, artificial intelligence, information theory, operational research, soft computing, communications, linguistic theory, and others. Integrated intelligent decision and control systems involve three primary hierarchical levels, namely organization, coordination and execution levels. As we proceed from the be performed organization to the execution level, the precision about the jobs to increases and accordingly the intelligence required for these jobs decreases. This is in compliance with the principle of increasing precision with decreasing intelligence (IPOI) known from the management field and theoretically established by Saridis using information theory concepts. This book is concerned with intelligent systems and techniques and gives emphasis on the computational and processing issues. Control issues are not included here. The contributions of the book are presented in four parts as follows.

Download or read book Land Applications of Radar Remote Sensing written by Damien Closson and published by BoD – Books on Demand. This book was released on 2014-06-11 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to demonstrate the use of SAR data in three application domains, i.e. land cover (Part II), topography (Part III), and land motion (Part IV). These are preceded by Part I, where an extensive and complete review on speckle and adaptive filtering is provided, essential for the understanding of SAR images. Part II is dedicated to land cover mapping. Part III is devoted to the generation of Digital Elevation Models based on radargrammetry and on a wise fusion (by considering sensor characteristic and acquisition geometry) of interferometric and photogrammetric elevation data. Part IV provides a contribution to three applications related to land motion.

Download or read book Theoretical and Practical Advances in Computer based Educational Measurement written by Bernard P. Veldkamp and published by Springer. This book was released on 2019-07-05 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book presents a large number of innovations in the world of operational testing. It brings together different but related areas and provides insight in their possibilities, their advantages and drawbacks. The book not only addresses improvements in the quality of educational measurement, innovations in (inter)national large scale assessments, but also several advances in psychometrics and improvements in computerized adaptive testing, and it also offers examples on the impact of new technology in assessment. Due to its nature, the book will appeal to a broad audience within the educational measurement community. It contributes to both theoretical knowledge and also pays attention to practical implementation of innovations in testing technology.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993-04 with total page 1774 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Distributed Optimization and Statistical Learning Via the Alternating Direction Method of Multipliers written by Stephen Boyd and published by Now Publishers Inc. This book was released on 2011 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surveys the theory and history of the alternating direction method of multipliers, and discusses its applications to a wide variety of statistical and machine learning problems of recent interest, including the lasso, sparse logistic regression, basis pursuit, covariance selection, support vector machines, and many others.