Abstract
Stochastic Primal-Dual Hybrid Gradient (SPDHG) is an algorithm proposed by Chambolle et al. (SIAM J Optim 28:2783–2808) to efficiently solve a wide class of nonsmooth large-scale optimization problems. Alacaoglu et al. (SIAM J Optim 32:1288–1318, 2022) filled an important gap and proved its almost sure convergence for serial sampling. In this paper, we study the performance of SPDHG with arbitrary sampling (not necessarily serial sampling) and its applications to parallel magnetic resonance imaging (MRI), where data from different coils are randomly selected at each iteration. In order to do this, we extend the convergence result of Alacaoglu et al. and prove the almost sure convergence of SPDHG for any arbitrary sampling. We then apply SPDHG on real MRI data using a wide range of random sampling methods and compare its performance across a range of settings, including mini-batch size and step size parameters. We show that the sampling can significantly affect the convergence speed of SPDHG and that for many cases an optimal sampling can be identified.
Original language | English |
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Article number | 25 |
Journal | Journal of Mathematical Imaging and Vision |
Volume | 67 |
Issue number | 3 |
Early online date | 17 Apr 2025 |
DOIs | |
Publication status | Published - 17 Apr 2025 |
Data Availability Statement
No datasets were generated or analysed during the current study.Funding
MJE and CD acknowledge support from the EPSRC (EP/S026045/1). MJE is also supported by EPSRC (EP/T026693/1), the Faraday Institution (EP/T007745/1) and the Leverhulme Trust (ECF-2019-478). EBG acknowledges the Mexican Council of Science and Technology (CONACyT).
Funders | Funder number |
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Consejo Nacional de Humanidades, Ciencias y Tecnologías | |
Engineering and Physical Sciences Research Council | EP/S026045/1, EP/T026693/1 |
Faraday Institution | EP/T007745/1 |
Leverhulme Trust | ECF-2019-478 |
Keywords
- Inverse problems
- Parallel MRI
- Primal-dual methods
- Stochastic optimization
ASJC Scopus subject areas
- Statistics and Probability
- Modelling and Simulation
- Condensed Matter Physics
- Computer Vision and Pattern Recognition
- Geometry and Topology
- Applied Mathematics