Probabilistic Solution of Inverse Problems

Item

Title
en_US Probabilistic Solution of Inverse Problems
Creator
en_US Marroquin, Jose Luis
Date
2004-10-20T20:03:41Z
Date Available
2004-10-20T20:03:41Z
Date Issued
en_US 1985-09-01
Identifier
en_US AITR-860
Abstract
en_US In this thesis we study the general problem of reconstructing a function, defined on a finite lattice from a set of incomplete, noisy and/or ambiguous observations. The goal of this work is to demonstrate the generality and practical value of a probabilistic (in particular, Bayesian) approach to this problem, particularly in the context of Computer Vision. In this approach, the prior knowledge about the solution is expressed in the form of a Gibbsian probability distribution on the space of all possible functions, so that the reconstruction task is formulated as an estimation problem. Our main contributions are the following: (1) We introduce the use of specific error criteria for the design of the optimal Bayesian estimators for several classes of problems, and propose a general (Monte Carlo) procedure for approximating them. This new approach leads to a substantial improvement over the existing schemes, both regarding the quality of the results (particularly for low signal to noise ratios) and the computational efficiency. (2) We apply the Bayesian appraoch to the solution of several problems, some of which are formulated and solved in these terms for the first time. Specifically, these applications are: teh reconstruction of piecewise constant surfaces from sparse and noisy observationsl; the reconstruction of depth from stereoscopic pairs of images and the formation of perceptual clusters. (3) For each one of these applications, we develop fast, deterministic algorithms that approximate the optimal estimators, and illustrate their performance on both synthetic and real data. (4) We propose a new method, based on the analysis of the residual process, for estimating the parameters of the probabilistic models directly from the noisy observations. This scheme leads to an algorithm, which has no free parameters, for the restoration of piecewise uniform images. (5) We analyze the implementation of the algorithms that we develop in non-conventional hardware, such as massively parallel digital machines, and analog and hybrid networks.
Extent
en_US 206 p.
12771133 bytes
10024699 bytes
Format
application/postscript
application/pdf
Language
en_US
Relation
en_US AITR-860
Subject
en_US inverse problems
en_US computer vision
en_US surface interpolation
en_US simage restoration
en_US Markov random fields
en_US optimal estimation
en_US simulated annealing