Non-line-of-sight Imaging

TL;DR

This paper reviews recent advances in non-line-of-sight imaging, which uses advanced sensors and inverse methods to reconstruct 3D scenes outside the direct view, enabling imaging around corners.

Contribution

It provides a comprehensive overview of recent progress and future prospects in NLOS imaging techniques and applications.

Findings

Recent sensors enable picosecond-accurate photon detection.

Inverse methods allow 3D scene reconstruction from scattered photons.

NLOS imaging can see around corners and beyond direct line of sight.

Abstract

Emerging single-photon-sensitive sensors combined with advanced inverse methods to process picosecond-accurate time-stamped photon counts have given rise to unprecedented imaging capabilities. Rather than imaging photons that travel along direct paths from a source to an object and back to the detector, non-line-of-sight (NLOS) imaging approaches analyse photons {scattered from multiple surfaces that travel} along indirect light paths to estimate 3D images of scenes outside the direct line of sight of a camera, hidden by a wall or other obstacles. Here we review recent advances in the field of NLOS imaging, discussing how to see around corners and future prospects for the field.