Solving Continuous-Domain Problems Exactly with Multiresolution B-Splines
T. Debarre, J. Fageot, H. Gupta, M. Unser
Proceedings of the Forty-Fourth IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP'19), Brighton, United Kingdom, May 12-17, 2019, pp. 5122–5126.
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.
@INPROCEEDINGS(http://bigwww.epfl.ch/publications/debarre1901.html, AUTHOR="Debarre, T. and Fageot, J. and Gupta, H. and Unser, M.", TITLE="Solving Continuous-Domain Problems Exactly with Multiresolution \mbox{{B}-Splines}", BOOKTITLE="Proceedings of the Forty-Fourth IEEE International Conference on Acoustics, Speech, and Signal Processing ({ICASSP'19})", YEAR="2019", editor="", volume="", series="", pages="5122--5126", address="Brighton, United Kingdom", month="May 12-17,", organization="", publisher="", note="")