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arXiv · 1904.00423

A Memory-efficient Algorithm for Large-scale Sparsity Regularized Image Reconstruction

Greg Ongie·Naveen Murthy·Laura Balzano·Jeffrey A. Fessler
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Abstract

We derive a memory-efficient first-order variable splitting algorithm for convex image reconstruction problems with non-smooth regularization terms. The algorithm is based on a primal-dual approach, where one of the dual variables is updated using a step of the Frank-Wolfe algorithm, rather than the typical proximal point step used in other primal-dual algorithms. We show in certain cases this results in an algorithm with far less memory demand than other first-order methods based on proximal mappings. We demonstrate the algorithm on the problem of sparse-view X-ray computed tomography (CT) reconstruction with non-smooth edge-preserving regularization and show competitive run-time with other state-of-the-art algorithms while using much less memory.

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Greg Ongie, Naveen Murthy, Laura Balzano, Jeffrey A. Fessler. 2019-03-31. A Memory-efficient Algorithm for Large-scale Sparsity Regularized Image Reconstruction. https://arxiv.org/abs/1904.00423

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