Real-time quadrature lock-in discrimination imaging through scattering media

TL;DR

This paper presents a real-time imaging technique through scattering media using a simplified algorithm and parallel processing, enabling fast, low-cost imaging suitable for applications like navigation in poor visibility.

Contribution

The authors introduce a novel real-time imaging method through scattering media that significantly outperforms conventional techniques in speed and simplicity.

Findings

Achieved imaging rates several times the flicker frequency of the eye.

Speedup of more than three orders of magnitude over traditional methods.

Demonstrated utility in navigation under poor visibility conditions.

Abstract

Numerous everyday situations like navigation, medical imaging and rescue operations require viewing through optically inhomogeneous media. This is a challenging task as photons, instead of traversing ballistically, propagate predominantly diffusively due to random multiple scattering off the inhomogenieties. Imaging {\it in real-time} with ballistic light under continuous-wave illumination is even more challenging due to the extremely weak signal, necessitating voluminous data-processing. In this paper, we report imaging through strongly scattering media in real-time and at rates several times the critical flicker frequency of the eye, so that motion is perceived as continuous. Two factors contributed to the speedup of {\it more than three orders of magnitude} over conventional techniques - the use of a simplified algorithm enabling processing of data on the fly, and the utilisation of task and data parallelization capabilities of typical desktop computers. The extreme simplicity and low cost promises great utility of this technique. As an example, navigation under poor visibility is examined.