Live Iterative Ptychography with projection-based algorithms

TL;DR

This paper introduces a live ptychographic phase retrieval method that allows real-time imaging during data collection, enabling immediate feedback and adaptive scanning with comparable computational resources.

Contribution

It proposes a novel modification of projection-based algorithms for live ptychography, inspired by audio processing techniques, improving real-time reconstruction quality.

Findings

Live algorithms enable immediate visual feedback during experiments.

The method reconstructs large objects with fixed computational resources.

Live variants can outperform traditional methods in reconstruction quality.

Abstract

In this work, we demonstrate that the ptychographic phase problem can be solved in a live fashion during scanning, while data is still being collected. We propose a generally applicable modification of the widespread projection-based algorithms such as Error Reduction (ER) and Difference Map (DM). This novel variant of ptychographic phase retrieval enables immediate visual feedback during experiments, reconstruction of arbitrary-sized objects with a fixed amount of computational resources, and adaptive scanning. By building upon the Real-Time Iterative Spectrogram Inversion (RTISI) family of algorithms from the audio processing literature, we show that live variants of projection-based methods such as DM can be derived naturally and may even achieve higher-quality reconstructions than their classic non-live counterparts with comparable effective computational load.