Investigation of the convergence properties of an iterative image restoration algorithm.
Name:
azu_td_9506980_sip1_m.pdf
Size:
2.629Mb
Format:
PDF
Description:
azu_td_9506980_sip1_m.pdf
Author
Elfendahl, Michael Preston.Issue Date
1994Committee Chair
Hunt, B.R.
Metadata
Show full item recordPublisher
The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Abstract
Iterative algorithms for image restoration which include the use of prior knowledge of the solution in their design have proven useful in super resolution imaging. In this dissertation, a Bayesian estimation method is presented called the Poisson Maximum A Posteriori (MAP) image restoration algorithm. The Poisson MAP algorithm is shown to be slightly different in its design but similar in super resolution ability to the Poisson Maximum Likelihood (ML) algorithm. Numerical simulations demonstrate that the Poisson MAP algorithm in almost all cases achieves legitimate bandwidth extension and thus achieves super resolution. Practical criteria for indicating when the algorithm has numerically converged are reviewed. The advantages of these criteria are discussed. The theoretical convergence properties of the Poisson MAP algorithm are investigated. The iterative algorithm is viewed as a nonlinear vector mapping in the N-dimensional real Euclidean vector space, Rᴺ. The necessary and sufficient conditions for nonlinear iterative methods of this type to converge are discussed and are shown to be satisfied in certain cases. Although convergence in some cases can only be demonstrated experimentally, convergence can almost always be guaranteed with the right choice of starting vector in cases where super resolution is most needed.Type
textDissertation-Reproduction (electronic)
Degree Name
Ph.D.Degree Level
doctoralDegree Program
Applied MathematicsGraduate College