Bayesian Modeling of Uncertainty in Low-Level Vision

Bayesian Modeling of Uncertainty in Low-Level Vision PDF Author: Richard Szeliski
Publisher: Springer Science & Business Media
ISBN: 1461316375
Category : Computers
Languages : en
Pages : 206

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Book Description
Vision has to deal with uncertainty. The sensors are noisy, the prior knowledge is uncertain or inaccurate, and the problems of recovering scene information from images are often ill-posed or underconstrained. This research monograph, which is based on Richard Szeliski's Ph.D. dissertation at Carnegie Mellon University, presents a Bayesian model for representing and processing uncertainty in low level vision. Recently, probabilistic models have been proposed and used in vision. Sze liski's method has a few distinguishing features that make this monograph im portant and attractive. First, he presents a systematic Bayesian probabilistic estimation framework in which we can define and compute the prior model, the sensor model, and the posterior model. Second, his method represents and computes explicitly not only the best estimates but also the level of uncertainty of those estimates using second order statistics, i.e., the variance and covariance. Third, the algorithms developed are computationally tractable for dense fields, such as depth maps constructed from stereo or range finder data, rather than just sparse data sets. Finally, Szeliski demonstrates successful applications of the method to several real world problems, including the generation of fractal surfaces, motion estimation without correspondence using sparse range data, and incremental depth from motion.

Bayesian Modeling of Uncertainty in Low-Level Vision

Bayesian Modeling of Uncertainty in Low-Level Vision PDF Author: Richard Szeliski
Publisher: Springer Science & Business Media
ISBN: 1461316375
Category : Computers
Languages : en
Pages : 206

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Book Description
Vision has to deal with uncertainty. The sensors are noisy, the prior knowledge is uncertain or inaccurate, and the problems of recovering scene information from images are often ill-posed or underconstrained. This research monograph, which is based on Richard Szeliski's Ph.D. dissertation at Carnegie Mellon University, presents a Bayesian model for representing and processing uncertainty in low level vision. Recently, probabilistic models have been proposed and used in vision. Sze liski's method has a few distinguishing features that make this monograph im portant and attractive. First, he presents a systematic Bayesian probabilistic estimation framework in which we can define and compute the prior model, the sensor model, and the posterior model. Second, his method represents and computes explicitly not only the best estimates but also the level of uncertainty of those estimates using second order statistics, i.e., the variance and covariance. Third, the algorithms developed are computationally tractable for dense fields, such as depth maps constructed from stereo or range finder data, rather than just sparse data sets. Finally, Szeliski demonstrates successful applications of the method to several real world problems, including the generation of fractal surfaces, motion estimation without correspondence using sparse range data, and incremental depth from motion.

Bayesian Modeling of Uncertainty in Low-Level Vision

Bayesian Modeling of Uncertainty in Low-Level Vision PDF Author: Richard Szeliski
Publisher: Springer
ISBN: 9781461316381
Category : Computers
Languages : en
Pages : 198

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Book Description
Vision has to deal with uncertainty. The sensors are noisy, the prior knowledge is uncertain or inaccurate, and the problems of recovering scene information from images are often ill-posed or underconstrained. This research monograph, which is based on Richard Szeliski's Ph.D. dissertation at Carnegie Mellon University, presents a Bayesian model for representing and processing uncertainty in low level vision. Recently, probabilistic models have been proposed and used in vision. Sze liski's method has a few distinguishing features that make this monograph im portant and attractive. First, he presents a systematic Bayesian probabilistic estimation framework in which we can define and compute the prior model, the sensor model, and the posterior model. Second, his method represents and computes explicitly not only the best estimates but also the level of uncertainty of those estimates using second order statistics, i.e., the variance and covariance. Third, the algorithms developed are computationally tractable for dense fields, such as depth maps constructed from stereo or range finder data, rather than just sparse data sets. Finally, Szeliski demonstrates successful applications of the method to several real world problems, including the generation of fractal surfaces, motion estimation without correspondence using sparse range data, and incremental depth from motion.

Encyclopedia of Computer Science and Technology

Encyclopedia of Computer Science and Technology PDF Author: Allen Kent
Publisher: CRC Press
ISBN: 1000445011
Category : Computers
Languages : en
Pages : 413

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Book Description
Volume 38 - Supplement 23: Algorithms for Designing Multimedia Storage Servers to Models and Architectures. Covering more than basic computer commands and procedures, this encyclopaedia summarizes how technology has developed, the future of computer programs and applications, and the significance of computer components. Following an introduction and overview, there are approximately 750 to 800 entries.

Stereo vision-based road condition monitoring

Stereo vision-based road condition monitoring PDF Author: Brunken, Hauke
Publisher: Universitätsverlag der TU Berlin
ISBN: 3798332053
Category : Technology & Engineering
Languages : en
Pages : 188

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Book Description
When planning road construction measures, it is essential to have up-to-date information on road conditions. If this information is not to be obtained manually, it is currently obtained using laser scanners mounted on mobile mapping vehicles, which can measure the 3D road profile. However, a large number of mobile mapping vehicles would be necessary to record an entire road network on a regular basis. Since 2D road damages can be found automatically on monocular camera images, the idea was born to use a stereo camera system to capture the 3D profile of roads. With stereo camera systems, it would be possible to equip a large number of vehicles and regularly collect data from large road networks. In this thesis, the potential applications of a stereo camera system for measuring road profiles, which is mounted behind the windshield of a vehicle, are investigated. Since this requires a calibration of the stereo camera system, but the effort for the user should be kept low, the camera self-calibration for this application is also examined. 3D reconstruction from stereoscopic images is a well-studied topic, but its application on road surfaces with little and repetitive textures requires special algorithms. For this reason, a new stereo method was developed. It is based on the plane-sweep approach in combination with semi-global matching. It was tested with different measures for pixel comparison. Furthermore, the plane-sweep approach was implemented in a neural network that solves the stereo correspondence problem in a single step. It uses the stereoscopic images as input and provides an elevation image as output. A completely new approach was developed for the self-calibration of mono cameras and stereo camera systems. Previous methods search for feature points in several images of the same scene. The points are matched between the images and used for the calibration. In contrast to these methods, the proposed method uses feature maps instead of feature points to compare multiple views of one and the same plane. To estimate the unknown parameters, the backpropagation algorithm is used together with the gradient descent method. The measurements obtained by stereoscopic image processing were compared with those obtained by industrial laser scanners. They show that both measurements are very close to each other and that a stereoscopic camera system is in principle suitable for capturing the surface profile of a road. Experiments show that the proposed self-calibration method is capable of estimating all parameters of a complex camera model, including lens distortion, with high precision. Bei der Planung von Straßenbaumaßnahmen ist es unabdingbar, über aktuelle Informationen über den Straßenzustand zu verfügen. Sollen diese Informationen nicht manuell gewonnen werden, werden derzeit Messfahrzeug mit Laserscannern verwendet, welche das 3D-Straßenprofil vermessen können. Für die regelmäßige Erfassung eines gesamten Straßennetzes wäre jedoch eine große Anzahl von Messfahrzeugen erforderlich. Da 2D-Straßenschäden automatisch auf monokularen Kamerabildern gefunden werden können, entstand die Idee, ein Stereokamerasystem zur Erfassung des 3D-Profils zu verwenden. Eine große Anzahl von Fahrzeugen könnte damit ausgerüstet werden und es könnten regelmäßig Daten von großen Straßennetzen erfasst werden. In dieser Arbeit werden die Einsatzmöglichkeiten eines Stereokamerasystems zur Messung von Straßenprofilen untersucht, dass sich hinter der Windschutzscheibe eines Fahrzeugs befindet. Da hierzu das Stereokamerasystems kalibriert sein muss, der Aufwand für den Anwender aber geringgehalten werden soll, wird außerdem die Selbstkalibrierung für diesen Einsatzzweck untersucht. Die 3D-Rekonstruktion aus stereoskopischen Bildern ist ein viel untersuchtes Thema, aber ihre Anwendung auf Straßenoberflächen mit wenig und sich wiederholenden Texturen erfordert spezielle Algorithmen. Aus diesem Grund wurde ein neues Stereoverfahren entwickelt. Es basiert auf dem Plane-sweep-Ansatz in Kombination mit Semi-global Matching. Es wurde mit verschiedene Maßen für den Vergleich von Pixeln getestet. Darüber hinaus wurde der Plane-sweep-Ansatz in einem neuronalen Netzwerk implementiert, das das Stereo-Korrespondenzproblem in einem einzigen Schritt löst. Es verwendet die stereoskopischen Bilder als Eingabe und liefert als Ausgabe ein Höhenbild. Für die Selbstkalibrierung von Monokameras und Stereokamerasystemen wurde ein völlig neuer Ansatz entwickelt. Bisherige Methoden suchen nach Merkmalspunkten in mehreren Bildern der gleichen Szene. Die Punkte werden zwischen den Bildern zugeordnet und für die Kalibrierung verwendet. Die vorgeschlagene Methode verwendet anstelle von Merkmalspunkten Feature-Maps um mehrere Ansichten derselben Ebene zu vergleichen. Zur Schätzung der unbekannten Parameter wird der Backpropagation-Algorithmus zusammen mit dem Gradientenabstiegsverfahren verwendet. Die durch stereoskopische Bildverarbeitung erhaltenen Messungen wurden mit Messungen von industriellen Laserscannern verglichen. Sie zeigen, dass beide sehr nahe beieinander liegen und dass ein Stereokamerasystem für die Erfassung des Oberflächenprofils einer Straße grundsätzlich geeignet ist. Experimente zeigen, dass die neue Selbstkalibrierungsmethode in der Lage ist, alle Parameter eines komplexen Kameramodells, einschließlich der Linsenverzerrung, mit hoher Präzision abzuschätzen.

View Synthesis Using Stereo Vision

View Synthesis Using Stereo Vision PDF Author: Daniel Scharstein
Publisher: Springer
ISBN: 3540487255
Category : Computers
Languages : en
Pages : 173

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Book Description
Image-based rendering, as an area of overlap between computer graphics and computer vision, uses computer vision techniques to aid in sythesizing new views of scenes. Image-based rendering methods are having a substantial impact on the field of computer graphics, and also play an important role in the related field of multimedia systems, for applications such as teleconferencing, remote instruction and surgery, virtual reality and entertainment. The book develops a novel way of formalizing the view synthesis problem under the full perspective model, yielding a clean, linear warping equation. It shows new techniques for dealing with visibility issues such as partial occlusion and "holes". Furthermore, the author thoroughly re-evaluates the requirements that view synthesis places on stereo algorithms and introduces two novel stereo algorithms specifically tailored to the application of view synthesis.

Biomedical Image Understanding

Biomedical Image Understanding PDF Author: Joo-Hwee Lim
Publisher: John Wiley & Sons
ISBN: 1118957571
Category : Technology & Engineering
Languages : en
Pages : 524

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Book Description
A comprehensive guide to understanding and interpreting digital images in medical and functional applications Biomedical Image Understanding focuses on image understanding and semantic interpretation, with clear introductions to related concepts, in-depth theoretical analysis, and detailed descriptions of important biomedical applications. It covers image processing, image filtering, enhancement, de-noising, restoration, and reconstruction; image segmentation and feature extraction; registration; clustering, pattern classification, and data fusion. With contributions from experts in China, France, Italy, Japan, Singapore, the United Kingdom, and the United States, Biomedical Image Understanding: Addresses motion tracking and knowledge-based systems, two areas which are not covered extensively elsewhere in a biomedical context Describes important clinical applications, such as virtual colonoscopy, ocular disease diagnosis, and liver tumor detection Contains twelve self-contained chapters, each with an introduction to basic concepts, principles, and methods, and a case study or application With over 150 diagrams and illustrations, this bookis an essential resource for the reader interested in rapidly advancing research and applications in biomedical image understanding.

Mathematical Perspectives on Neural Networks

Mathematical Perspectives on Neural Networks PDF Author: Paul Smolensky
Publisher: Psychology Press
ISBN: 1134772947
Category : Psychology
Languages : en
Pages : 865

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Book Description
Recent years have seen an explosion of new mathematical results on learning and processing in neural networks. This body of results rests on a breadth of mathematical background which even few specialists possess. In a format intermediate between a textbook and a collection of research articles, this book has been assembled to present a sample of these results, and to fill in the necessary background, in such areas as computability theory, computational complexity theory, the theory of analog computation, stochastic processes, dynamical systems, control theory, time-series analysis, Bayesian analysis, regularization theory, information theory, computational learning theory, and mathematical statistics. Mathematical models of neural networks display an amazing richness and diversity. Neural networks can be formally modeled as computational systems, as physical or dynamical systems, and as statistical analyzers. Within each of these three broad perspectives, there are a number of particular approaches. For each of 16 particular mathematical perspectives on neural networks, the contributing authors provide introductions to the background mathematics, and address questions such as: * Exactly what mathematical systems are used to model neural networks from the given perspective? * What formal questions about neural networks can then be addressed? * What are typical results that can be obtained? and * What are the outstanding open problems? A distinctive feature of this volume is that for each perspective presented in one of the contributed chapters, the first editor has provided a moderately detailed summary of the formal results and the requisite mathematical concepts. These summaries are presented in four chapters that tie together the 16 contributed chapters: three develop a coherent view of the three general perspectives -- computational, dynamical, and statistical; the other assembles these three perspectives into a unified overview of the neural networks field.

Proceedings IWISP '96, 4–7 November 1996; Manchester, UK

Proceedings IWISP '96, 4–7 November 1996; Manchester, UK PDF Author: Basil G. Mertzios
Publisher: Elsevier
ISBN: 0080539769
Category : Technology & Engineering
Languages : en
Pages : 729

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Book Description
The papers in this volume focus on the most modern and critical aspects of Image and Signal Processing and related areas that have a significant impact in our society. The papers may be categorized in the following four major parts. Coding and Compression (image coding, image subband, wavelet coding and representation, video coding, motion estimation and multimedia); Image Processing and Pattern Recognition (image analysis, edge detection, segmentation, image enhancement and restoration, adaptive systems, colour processing, pattern and object recognition and classification); Fast Processing Techniques (computational methods, VLSI DSP architectures); Theory and Applications (identificiation and modelling, multirate filter banks, wavelets in image and signal processing, biomedical and industrial applications). The authors of these exceptionally high-quality papers form an interesting group, originating from the five continents, representing 33 countries.

Encyclopedia of Library and Information Science

Encyclopedia of Library and Information Science PDF Author: Allen Kent
Publisher: CRC Press
ISBN: 9780824720704
Category : Language Arts & Disciplines
Languages : en
Pages : 442

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Book Description
This is the 70th encyclopaedia of library and information science. It covers topics such as: intelligent systems for problem analysis in organizations; interactive system design; international models of school library development; lexicalization in natural language generation; and more.

Statistical Image Processing and Multidimensional Modeling

Statistical Image Processing and Multidimensional Modeling PDF Author: Paul Fieguth
Publisher: Springer Science & Business Media
ISBN: 1441972943
Category : Mathematics
Languages : en
Pages : 465

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Book Description
Images are all around us! The proliferation of low-cost, high-quality imaging devices has led to an explosion in acquired images. When these images are acquired from a microscope, telescope, satellite, or medical imaging device, there is a statistical image processing task: the inference of something—an artery, a road, a DNA marker, an oil spill—from imagery, possibly noisy, blurry, or incomplete. A great many textbooks have been written on image processing. However this book does not so much focus on images, per se, but rather on spatial data sets, with one or more measurements taken over a two or higher dimensional space, and to which standard image-processing algorithms may not apply. There are many important data analysis methods developed in this text for such statistical image problems. Examples abound throughout remote sensing (satellite data mapping, data assimilation, climate-change studies, land use), medical imaging (organ segmentation, anomaly detection), computer vision (image classification, segmentation), and other 2D/3D problems (biological imaging, porous media). The goal, then, of this text is to address methods for solving multidimensional statistical problems. The text strikes a balance between mathematics and theory on the one hand, versus applications and algorithms on the other, by deliberately developing the basic theory (Part I), the mathematical modeling (Part II), and the algorithmic and numerical methods (Part III) of solving a given problem. The particular emphases of the book include inverse problems, multidimensional modeling, random fields, and hierarchical methods.