Sparsity-regularized coded ptychography for robust and efficient lensless microscopy on a chip

TL;DR

This paper presents a sparsity-regularized ptychography method called PPTV that significantly reduces measurement requirements for high-quality lensless microscopy, enabling faster and more efficient imaging on a chip.

Contribution

Introduction of the PPTV algorithm that integrates total variation regularization into coded ptychography, reducing measurements needed without hardware changes.

Findings

Accurate reconstructions with as few as eight measurements.

Robustness and stability confirmed through convergence analysis.

Experimental validation with an optical prototype.

Abstract

Coded ptychography has emerged as a powerful technique for high-throughput, high-resolution lensless imaging. However, the trade-off between acquisition speed and image quality remains a significant challenge. To address this, we introduce a novel sparsity-regularized approach to coded ptychography that dramatically reduces the number of required measurements while maintaining high reconstruction quality. The reported approach, termed the ptychographic proximal total-variation (PPTV) solver, formulates the reconstruction task as a total variation regularized optimization problem. Unlike previous implementations that rely on specialized hardware or illumination schemes, PPTV integrates seamlessly into existing coded ptychography setups. Through comprehensive numerical simulations, we demonstrate that PPTV-driven coded ptychography can produce accurate reconstructions with as few as eight intensity measurements, a significant reduction compared to conventional methods. Convergence analysis confirms the robustness and stability of the PPTV algorithm. Experimental results from our optical prototype, featuring a disorder-engineered surface for wavefront modulation, validate PPTV's ability to achieve high-throughput, high-resolution imaging with a substantially reduced measurement burden. By enabling high-quality reconstructions from fewer measurements, PPTV paves the way for more compact, efficient, and cost-effective lensless microscopy systems on a chip, with potential applications in digital pathology, endoscopy, point-of-care diagnostics, and high-content screening.