Learning-based Image Reconstruction via Parallel Proximal Algorithm

TL;DR

This paper introduces a novel image reconstruction method that replaces traditional sparsity regularization with a trainable prior learned through an extended parallel proximal algorithm, demonstrated on fluorescence microscope deconvolution.

Contribution

It generalizes TV regularization by integrating a data-adaptive, trainable prior into the FPPA framework without extra inner iterations, enabling end-to-end learning.

Findings

Effective deconvolution in fluorescence microscopy

Trainable prior improves reconstruction quality

End-to-end framework simplifies implementation

Abstract

In the past decade, sparsity-driven regularization has led to advancement of image reconstruction algorithms. Traditionally, such regularizers rely on analytical models of sparsity (e.g. total variation (TV)). However, more recent methods are increasingly centered around data-driven arguments inspired by deep learning. In this letter, we propose to generalize TV regularization by replacing the l1-penalty with an alternative prior that is trainable. Specifically, our method learns the prior via extending the recently proposed fast parallel proximal algorithm (FPPA) to incorporate data-adaptive proximal operators. The proposed framework does not require additional inner iterations for evaluating the proximal mappings of the corresponding learned prior. Moreover, our formalism ensures that the training and reconstruction processes share the same algorithmic structure, making the end-to-end implementation intuitive. As an example, we demonstrate our algorithm on the problem of deconvolution in a fluorescence microscope.