Toward Long Distance, Sub-diffraction Imaging Using Coherent Camera Arrays

TL;DR

This paper proposes a novel long-distance imaging method using coherent camera arrays and phase retrieval algorithms, achieving significant resolution improvements beyond the diffraction limit in both simulations and real experiments.

Contribution

It introduces a coherent camera array system for long-range imaging that surpasses diffraction limits, with a new single-shot Fourier ptychography approach.

Findings

Achieved 10x resolution enhancement in simulations.

Real scene experiments showed 4x-7x resolution gains.

Demonstrated effective phase retrieval for high-resolution reconstruction.

Abstract

In this work, we propose using camera arrays coupled with coherent illumination as an effective method of improving spatial resolution in long distance images by a factor of ten and beyond. Recent advances in ptychography have demonstrated that one can image beyond the diffraction limit of the objective lens in a microscope. We demonstrate a similar imaging system to image beyond the diffraction limit in long range imaging. We emulate a camera array with a single camera attached to an X-Y translation stage. We show that an appropriate phase retrieval based reconstruction algorithm can be used to effectively recover the lost high resolution details from the multiple low resolution acquired images. We analyze the effects of noise, required degree of image overlap, and the effect of increasing synthetic aperture size on the reconstructed image quality. We show that coherent camera arrays have the potential to greatly improve imaging performance. Our simulations show resolution gains of 10x and more are achievable. Furthermore, experimental results from our proof-of-concept systems show resolution gains of 4x-7x for real scenes. Finally, we introduce and analyze in simulation a new strategy to capture macroscopic Fourier Ptychography images in a single snapshot, albeit using a camera array.