Bayesian and Deterministic Spatio-Temporal Methods with Edge-Preserving Priors for Inverse Problems

14.12.2022, 12:15  –  Golm, Haus 9, 1.10
SFB-Seminar

Mirjeta Pasha (Tufts University)

Abstract: Inverse problems are ubiquitous in many fields of science such as engineering, biology, medical imaging, atmospheric science, and geophysics. Three emerging challenges on obtaining relevant solutions to large-scale and data-intensive inverse problems are ill-posedness of the problem, large dimensionality of the parameters, and the complexity of the model constraints. In this talk we discuss efficient methods for computing solutions to dynamic inverse problems, where both the quantities of interest and the forward operator may change at different time instances. We consider large-scale ill-posed problems that are made more challenging by their dynamic nature and, possibly, by the limited amount of available data per measurement step.

In the first part of the talk, to remedy these difficulties, we apply efficient regularization methods that enforce simultaneous regularization in space and time (such as edge enhancement at each time instant and proximity at consecutive time instants) and achieve this with low computational cost and enhanced accuracy.

In the remainder of the talk, we focus on designing spatio-temporal Bayesian Besov priors for computing the MAP estimate and quantifying uncertainties in large-scale and dynamic inverse problems.

Numerical examples from a wide range of applications, such as tomographic reconstruction, image deblurring, and multichannel dynamic tomography are used to illustrate the effectiveness of the described approaches.