Download or read book Mesures statistiques non param triques pour la segmentation d images et de vid os et minimisation par contours actifs written by Ariane Herbulot and published by . This book was released on 2007 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: La segmentation d'images et de séquences vidéo consiste à séparer les objets d'intérêt du reste de l'image. L'utilisation de contours actifs en utilisant une approche variationnelle repose sur la définition d'un critère de segmentation. Ce critère est ensuite dérivé à l'aide des gradients de forme, afin de parvenir à l'équation d'évolution du contour actif. Bien souvent ce critère dépend des caractéristiques de l'image et fait une hypothèse implicite sur les distributions de ces caractéristiques. Par exemple, considérer une fonction de la moyenne de l'intensité d'une région revient à faire une hypothèse gaussienne sur la distribution de cette intensité. Dans cette thèse, nous proposons de nous affranchir de ces hypothèses qui ne sont pas toujours respectées et de considérer les distributions les plus "réelles" possible en utilisant une estimation non-paramétrique de ces distributions. Nous présentons des critères issus de la théorie de l'information, comme l'entropie, afin de segmenter des zones de faible variabilité dans les images. Afin de prendre en compte plusieurs canaux comme les canaux couleur, l'entropie jointe et l'information mutuelle sont aussi utilisées. Lorsqu'une information a priori est connue, la divergence de Kullback-Leibler permet d'introduire une notion de distance à une segmentation de référence en cherchant à minimiser une "distance" entre distributions. Enfin, l'entropie jointe est utilisée afin de segmenter des objets en mouvement dans des séquences vidéo, que cela soit en ayant au préalable calculé un flot optique, ou en estimant de façon conjointe le mouvement avec la segmentation.

Download or read book Recalage non rigide d images m dicales volumiques written by Pascal Cachier and published by . This book was released on 2002 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le recalage non rigide d'images est un problème classique et important en vision par ordinateur qui revient à déformer une image afin qu'elle ressemble à une autre. Les techniques existantes, très nombreuses, sont généralement répertoriées selon l'information utilisée pour le recalage. D'un côté, les algorithmes iconiques utilisent l'intensité des images. De l'autre, les algorithmes géométriques utilisent des amers géométriques extraits des images, comme les bords d'un objet. Dans cette thèse, nous montrons d'abord que cette classification n'est pas assez fine pour expliquer certaines différences fondamentales entre le comportement de certains algorithmes. Nous proposons de ce fait de diviser la classe des algorithmes iconiques en deux : nous distinguons d'une part les algorithmes iconiques standard, et d'autre part les algorithmes de recalage d'amers iconiques. Nous introduisons une énergie générale de recalage d'amers iconiques, puis nous développons des instances particulières de cette énergie ayant des propriétés spéciales selon l'application visée : ajout de contraintes géométriques supplémentaires, invariance au biais non uniforme corrompant les images, régularisation vectorielle avec des effets croisés, invariance par échange des images. Nous montrons des applications de nos algorithmes en suivi du mouvement dans des séquences échographiques tridimensionnelles, en recalage intersujet de cerveaux, et en interpolation de formes et d'intensités.

Download or read book Medical Imaging 2004 written by J. Michael Fitzpatrick and published by SPIE-International Society for Optical Engineering. This book was released on 2004 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.

Download or read book M thodes variationnelles pour la segmentation d images partir de mod les written by Raphaël Prevost and published by . This book was released on 2013 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: La segmentation d'images médicales est depuis longtemps un sujet de recherche actif. Cette thèse traite des méthodes de segmentation basées modèles, qui sont un bon compromis entre généricité et capacité d'utilisation d'informations a priori sur l'organe cible. Notre but est de construire un algorithme de segmentation pouvant tirer profit d'une grande variété d'informations extérieures telles que des bases de données annotées (via l'apprentissage statistique), d'autres images du même patient (via la co-segmentation) et des interactions de l'utilisateur. Ce travail est basé sur la déformation de modèle implicite, une méthode variationnelle reposant sur une représentation implicite des formes. Après avoir amélioré sa formulation mathématique, nous montrons son potentiel sur des problèmes cliniques difficiles. Nous introduisons ensuite différentes généralisations, indépendantes mais complémentaires, visant à enrichir le modèle de forme et d'apparence utilisé. La diversité des applications cliniques traitées prouve la généricité et l'efficacité de nos contributions.

Download or read book CONTRIBUTION AU RECALAGE D IMAGES MEDICALES MULTIMODALES written by CHRISTOFOROS.. NIKOU and published by . This book was released on 1999 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: NOUS ABORDONS, DANS CETTE THESE, LE PROBLEME DU RECALAGE RIGIDE D'IMAGES MEDICALES MULTIMODALES 3D DU CERVEAU HUMAIN. DEUX APPROCHES SONT PROPOSEES POUR RENDRE LE RECALAGE ROBUSTE AUX DISSIMILARITES ENTRE IMAGES DUES A DES BRUITS NON GAUSSIENS, A L'EVOLUTION DE LESIONS, A DES ACQUISITIONS INCOMPLETES OU A DES INFORMATIONS NON REDONDANTES. UNE PREMIERE APPROCHE REPOSE SUR DES FONCTIONS DE SIMILARITE INTER-IMAGES ASSOCIEES A DES M-ESTIMATEURS ROBUSTES. LA TECHNIQUE A ETE EVALUEE DANS LE CADRE D'UN PROTOCOLE COMPARATIF ET S'EST AVEREE PERFORMANTE POUR LE RECALAGE D'IMAGES MULTIMODALES PRESENTANT DES DIFFERENCES IMPORTANTES D'INFORMATION. UNE SECONDE APPROCHE S'APPUIE SUR DES MODELES DEFORMABLES STATISTIQUEMENT CONTRAINTS MODELISANT LES RELATIONS SPATIALES ENTRE LES SURFACES DU CRANE ET DU CERVEAU CHEZ LE MEME INDIVIDU, AINSI QUE LES VARIABILITES ANATOMIQUES OBSERVEES DANS UNE POPULATION D'APPRENTISSAGE. CE MODELE PERMET NON SEULEMENT DE CONTRAINDRE LE RECALAGE DES STRUCTURES ANATOMIQUES MAIS FOURNIT AUSSI UNE PREDICTION DE LA POSITION SPATIALE D'AUTRES STRUCTURES ANATOMIQUES REPRESENTEES. CETTE SECONDE APPROCHE A ETE EVALUEE ET COMPAREE A L'APPROCHE PAR FONCTIONS DE SIMILARITE ROBUSTE. LA COMPARAISON A MONTRE QUE L'APPROCHE PAR MODELE DEFORMABLE CONDUIT A UNE PRECISION DE RECALAGE COMPARABLE A CELLE DES TECHNIQUES PAR FONCTIONS DE SIMILARITE. SA CAPACITE A TRAITER DES DONNEES MANQUANTES EST EN REVANCHE PLUS GRANDE, EN RAISON DES CONTRAINTES STATISTIQUES SPECIFIQUES APPORTEES PAR L'APPRENTISSAGE DU MODELE.

Download or read book Medical Image Computing and Computer Assisted Intervention MICCAI 2012 written by Nicholas Ayache and published by Springer. This book was released on 2012-08-28 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three-volume set LNCS 7510, 7511, and 7512 constitutes the refereed proceedings of the 15th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2012, held in Nice, France, in October 2012. Based on rigorous peer reviews, the program committee carefully selected 252 revised papers from 781 submissions for presentation in three volumes. The third volume includes 79 papers organized in topical sections on diffusion imaging: from acquisition to tractography; image acquisition, segmentation and recognition; image registration; neuroimage analysis; analysis of microscopic and optical images; image segmentation; diffusion weighted imaging; computer-aided diagnosis and planning; and microscopic image analysis.

Download or read book Local Approximation Techniques in Signal and Image Processing written by Vladimir I︠A︡kovlevich Katkovnik and published by SPIE-International Society for Optical Engineering. This book was released on 2006 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with a wide class of novel and efficient adaptive signal processing techniques developed to restore signals from noisy and degraded observations. These signals include those acquired from still or video cameras, electron microscopes, radar, X-rays, or ultrasound devices, and are used for various purposes, including entertainment, medical, business, industrial, military, civil, security, and scientific. In many cases useful information and high quality must be extracted from the imaging. However, often raw signals are not directly suitable for this purpose and must be processed in some way. Such processing is called signal reconstruction. This book is devoted to a recent and original approach to signal reconstruction based on combining two independent ideas: local polynomial approximation and the intersection of confidence interval rule.

Download or read book Magnetic Resonance Neurography written by Chhabra Avneesh and published by JAYPEE BROTHERS PUBLISHERS. This book was released on 2012-12-15 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, first of its kind, combination of concise explanations and focused clinical information satisfies the needs of practicing radiologists, neurologists, neurosurgeons, plastic and other peripheral nerve surgeons in need of a handy reference and technologists performing MRN studies. Written by two experts of magnetic resonance neurography (MRN) practitioners and educators, this thoroughly illustrated resource delivers how the information you need to perform and interpret peripheral nerve MR imaging studies with confidence. Concise descriptions and high quality illustrations combined wit.

Download or read book Product Life Cycle Management written by Max Giordano and published by John Wiley & Sons. This book was released on 2012-12-17 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a comprehensive view of the most recent major international research in the field of tolerancing, and is an excellent resource for anyone interested in Computer Aided Tolerating. It is organized into 4 parts. Part 1 focuses on the more general problems of tolerance analysis and synthesis, for tolerancing in mechanical design and manufacturing processes. Part 2 specifically highlights the simulation of assembly with defects, and the influence of tolerances on the quality of the assembly. Part 3 deals with measurement aspects, and quality control throughout the life cycle. Different measurement technologies and methods for estimating uncertainty are considered. In Part 4, different aspects of tolerancing and their interactions are explored, from the definition of functional requirement to measurement processes in a PLM approach.

Download or read book FAIR written by Jan Modersitzki and published by SIAM. This book was released on 2009-01-01 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whenever images taken at different times, from different viewpoints, and/or by different sensors need to be compared, merged, or integrated, image registration is required. Registration, also known as alignment, fusion, or warping, is the process of transforming data into a common reference frame. This book provides an overview of state-of-the-art registration techniques from theory to practice, numerous exercises, and via a supplementary Web page, free access to FAIR.m, a package that is based on the MATLAB software environment.

Download or read book Medical image computing and computer assisted intervention written by Nicholas Ayache and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

Download or read book Three Dimensional Elasticity written by and published by Elsevier. This book was released on 1988-04-01 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a thorough introduction to contemporary research in elasticity, and may be used as a working textbook at the graduate level for courses in pure or applied mathematics or in continuum mechanics. It provides a thorough description (with emphasis on the nonlinear aspects) of the two competing mathematical models of three-dimensional elasticity, together with a mathematical analysis of these models. The book is as self-contained as possible.

Download or read book Image Processing and Analysis written by Tony F. Chan and published by SIAM. This book was released on 2005-09-01 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book develops the mathematical foundation of modern image processing and low-level computer vision, bridging contemporary mathematics with state-of-the-art methodologies in modern image processing, whilst organizing contemporary literature into a coherent and logical structure. The authors have integrated the diversity of modern image processing approaches by revealing the few common threads that connect them to Fourier and spectral analysis, the machinery that image processing has been traditionally built on. The text is systematic and well organized: the geometric, functional, and atomic structures of images are investigated, before moving to a rigorous development and analysis of several image processors. The book is comprehensive and integrative, covering the four most powerful classes of mathematical tools in contemporary image analysis and processing while exploring their intrinsic connections and integration. The material is balanced in theory and computation, following a solid theoretical analysis of model building and performance with computational implementation and numerical examples.

Download or read book Numerical Methods for Image Registration written by Jan Modersitzki and published by Oxford University Press, USA. This book was released on 2004 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides an introduction to image registration with particular emphasis on numerical methods in medical imaging. Designed for researchers in industry and academia, it should also be a suitable study guide for graduate mathematicians, computer scientists and medical physicists.

Download or read book Ventricular Wall Motion written by Ulrich Sigwart and published by Thieme-Stratton Corporation. This book was released on 1984 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atlas of Vascular Anatomy written by Renan Uflacker and published by Lippincott Williams & Wilkins. This book was released on 2007 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt: This atlas details the vascular anatomy seen on angiographic images and in the new imaging modalities. The book presents the complete anatomy of the arteries, veins, and lymphatic system by body region. Full-color drawings are correlated with angiographic images to guide evaluation and management of vascular disease and performance of endovascular procedures. For this Second Edition, Dr. Uflacker has added more than 100 pictures and extensively reviewed the anatomical description of the vascular system. He has expanded the cardiac chapter with new CTA and MRI images, added percutaneous access where needed, and expanded the coverage of lower extremity anatomy.