Stanley Osher – författare

The goal of this book is to promote the use of level set methods by the many scientists and engineers working on moving interface problems. The authors provide some motivational/intuitive background on the scope and variety of moving interface problems and their mathematical formulation. They also review the pros and cons of traditional numerical techniques. The bulk of the book addresses the foundation of essential mathematical and numerical methods necessary for applying the level set method, with particular emphasis on problems in which the interface is just one part of a more complicated physical system. The book concludes with a few select example applications drawn from the authors' research. The book is intended for students and researchers interested in computation in the physical sciences, i.e.engineers, computational fluid dynamicists and applied mathematicians who want to use these methods for their own computations. It is suitable for use in a graduate level course on numerical methods, as a users guide to applying the methods, and as a general reference for mathematics related to level sets and the numerical solution of equations of ''Hamiltonian-Jacobi'' type.

The topic of level sets is currently very timely and useful. They are powerful numerical techniques for analyzing and computing interface motion in a host of application settings. In computer vision, it has been applied to stereo and segmentation, whereas in graphics it has been applied to the postproduction process of in-painting and 3-D model construction. Osher is co-inventor of the Level Set Methods, a pioneering framework introduced jointly with Professor James Sethian from the University of Berkeley in 1998. This methodology has been used up to now to provide solutions to a wide application range not limited to image processing, computer vision, robotics, fluid mechanics, crystallography, lithography, and computer graphics. The topic is of great interest, and the audience is not limited to students, professors, universities, and people working in the areas of graphics (post-production), video-based surveillance, visual inspection, augmented reality, document image processing, and medical image processing. These techniques are already employed to provide solutions and products in the industry too (Cognitech, Siemens, Philips, Focus Imaging).This book can be suitable for a short professional course related with the processing of visual information.

Introduction Imageprocessing,computervisionandcomputergraphicsarenowestablished - search areas. Pattern recognition and arti?cial intelligence were the origins of the explorationofthespace ofimages.Simplistic digitaltechniquesusedatthe beg- ning of 60’s for gray image processing operations have been now replaced with a complex mathematical framework that aims to exploit and understand images in two and three dimensions. Advances in computing power continue to make the use and processing of visual information an important part of our lives. The evolution of these techniques was a natural outcome of the need to p- cess an emerging informationspace, the space of natural images. Images in space and time are now a critical part of many human activities. First, pictures and now video streams were used to eternalize small and signi?cant moments of our life. Entertainment including movies, TV-programs and video games are part of our every-day life where capturing, editing, understanding and transmitting images are issues to be dealt with. The medical sector is also a major area for the use of images. The evolution of the acquisition devices led to new ways of capturing information, not visible by the human eye. Medical imaging is probably the most established market for processing visual information[405]. Visualization of c- plex structures and automated processing towards computer aided diagnosis is used more and more by the physicians in the diagnostic process. Safety and se- rity are also important areas where images and video play a signi?cant role [432].

Scope, Aims, and Audiences This book, Level Set Methods and Dynamic Implicit Surfaces is designed to serve two purposes: Parts I and II introduce the reader to implicit surfaces and level set methods. We have used these chapters to teach introductory courses on the material to students with little more than a fundamental math background. No prior knowledge of partial di?erential equations or numerical analysis is required. These ?rst eight chapters include enough detailed information to allow students to create working level set codes from scratch. Parts III and IV of this book are based on a series of papers published by us and our colleagues. For the sake of brevity, a few details have been occasionally omitted. These chapters do include thorough explanations and enough of the signi?cant details along with the appropriate references to allow the reader to get a ?rm grasp on the material. This book is an introduction to the subject. We have given examples of the utility of the method to a diverse (but by no means complete) collection of application areas. We have also tried to give complete numerical recipes and a self-contained course in the appropriate numerical analysis. We - lieve that this book will enable users to apply the techniques presented here to real problems.

This book takes readers on a tour through modern methods in image analysis and reconstruction based on level set and PDE techniques, the major focus being on morphological and geometric structures in images.

The book contains twenty-two original scienti?c research articles that address the state-of-the-art in using partial di?erential equations for image and signal processing. The articles arose from presentations given at the inter- tional conference on PDE-Based Image Processing and Related Inverse Pr- lems, held at the Centre of Mathematics for Applications, University of Oslo, Norway, August 8-12, 2005. The purpose of the conference was to bring together international - searchers to present various aspects of new developments in using numerical techniques for partial di?erential equations to analyse and process digital - ages. Various aspects of new trends and techniques in this ?eld were discussed in the conference, covering the following topics: • Level set methods and applications • Total variation regularization and other nonlinear ?lters • Noise analysis and removal • Image inpainting • Image dejittering • Optical ?ow estimation • Image segmentation • Image registration • Analysis and processing of MR images and brain mapping • Image construction techniques • Level set methods for inverse problems Inverse problems for partial di?erential equations have large areas of app- cations. Although image analysis and PDE inverse problems seem to be - related at a ?rst glance, there are many techniques used in one of these two areas that are useful for the other. One goal of the conference was to highlight some of the recent e?orts in merging some of the techniques for these two research areas.