Solving Continuous-domain Problems Exactly with Multiresolution B-splines

Autor: Harshit Gupta, Thomas Debarre, Julien Fageot, Michael Unser
Jazyk: angličtina
Předmět:
Zdroj: ICASSP 2019-2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
ICASSP
DOI: 10.1109/icassp.2019.8683214
Popis: We propose a discretization method for continuous-domain linear inverse problems with multiple-order total-variation (TV) regularization. It is based on a recent result that proves that such inverse problems have sparse polynomial-spline solutions. Our method consists in restricting the search space to splines with knots on a uniform grid, which results in a standard convex finite-dimensional problem. As basis functions for this search space, we use the B-splines matched to the regularization order, which are optimally localized. This leads to a well-conditioned, computationally feasible optimization task. Our proposed iterative multiresolution algorithm then refines the grid size until a desired level of accuracy is met and converges to sparse solutions of our inverse problem. Finally, we present experimental results that validate our approach.
Databáze: OpenAIRE