Fast Partial Fourier Transforms for Large-Scale Ptychography

TL;DR

This paper introduces a method using fast Partial Fourier Transforms to accelerate large-scale ptychography reconstructions, reducing computational costs while maintaining high-quality imaging results.

Contribution

It proposes a novel application of PFTs as a plug-and-play component to speed up ptychography algorithms without compromising image quality.

Findings

Accelerates convergence of ptychography algorithms

Reduces computational expense in large-scale imaging

Maintains high reconstruction quality

Abstract

Ptychography is a popular imaging technique that combines diffractive imaging with scanning microscopy. The technique consists of a coherent beam that is scanned across an object in a series of overlapping positions, leading to reliable and improved reconstructions. Ptychographic microscopes allow for large fields to be imaged at high resolution at additional computational expense. In this work, we explore the use of the fast Partial Fourier Transforms (PFTs), which efficiently compute Fourier coefficients corresponding to low frequencies. The core idea is to use the PFT in a plug-and-play manner to warm-start existing ptychography algorithms such as the ptychographic iterative engine (PIE). This approach reduces the computational budget required to solve the ptychography problem. Our numerical results show that our scheme accelerates the convergence of traditional solvers without sacrificing quality of reconstruction.