Classical first-order optimization methods for imaging inverse problems scale poorly with image resolution. Wavelet based multilevel strategies can accelerate convergence under strong blur, but their fixed coarse-to-fine schedules lose effectiveness in moderate-blur or noise-dominated regimes. In this work, we propose an adaptive multiresolution block coordinate Forward-Backward algorithm for image restoration. Multiresolution block selection is driven by the local magnitude of the proximal update via a stochastic non-smooth Gauss-Southwell rule applied to the wavelet decomposition of the image. This adaptive selection strategy dynamically balances updates across scales, emphasizing coarse or fine blocks according to the degradation regime. As a result, the proposed method automatically adapts to varying blur and noise levels without relying on a predefined hierarchical update scheme.
@article{arxiv.2603.01860,
title = {Multiresolution Adaptive Block-Coordinate Forward-Backward for Image Reconstruction},
author = {Edgar Desainte-Maréville and Marion Foare and Paulo Gonçalves and Nelly Pustelnik and Elisa Riccietti},
journal= {arXiv preprint arXiv:2603.01860},
year = {2026}
}