Speckle imaging with blind source separation and total variation deconvolution

TL;DR

This paper introduces a novel imaging method for highly diffusive environments using blind source separation and total variation deconvolution to achieve diffraction-limited resolution in speckle regimes, overcoming limitations of traditional coherent techniques.

Contribution

It presents a new approach combining blind source separation and deconvolution to improve imaging in speckle-dominated optical environments, enabling resolution beyond conventional methods.

Findings

Effective in imaging discrete scatterers.

Applicable to continuous objects.

Validated through numerical simulations.

Abstract

This work is concerned with optical imaging in strongly diffusive environments. We consider a typical setting in optical coherence tomography where a sample is probed by a collection of wavefields produced by a laser and propagating through a microscope. We operate in a scenario where the illuminations are in a speckle regime, namely fully randomized. This occurs when the light propagates deep in highly heterogeneous media. State-of-the-art coherent techniques are based on the ballistic part of the wavefield, that is the fraction of the wave that propagates freely and decays exponentially fast. In a speckle regime, the ballistic field is negligible compared to the scattered field, which precludes the use of coherent methods and different approaches are needed. We propose a strategy based on blind source separation and total variation deconvolution to obtain images with diffraction-limited resolution. The source separation allows us to isolate the fields diffused by the different scatterers to be imaged, while the deconvolution exploits the speckle memory effect to estimate the distance between these scatterers. Our method is validated with numerical simulations and is shown to be effective not only for imaging discrete scatterers, but also continuous objects.