Imaging of objects through a thin scattering layer using a spectrally and spatially separated reference

TL;DR

This paper presents a method to image objects through a thin scattering layer by using spectrally and spatially separated reference objects to approximate the point spread function, enabling clearer imaging despite scattering.

Contribution

It introduces a novel approach utilizing spectrally and spatially separated references to estimate the PSF for imaging through scattering media.

Findings

Spectrally shifted PSF correlates with a scaled version of the spatial PSF.

Deconvolution with the estimated PSF yields sharper images.

Method effectively improves image clarity through scattering layers.

Abstract

Incoherently illuminated or luminescent objects give rise to a low-contrast speckle-like pattern when observed through a thin diffusive medium, as such a medium effectively convolves their shape with a speckle-like point spread function (PSF). This point spread function can be extracted in the presence of a reference object of known shape. Here it is shown that reference objects that are both spatially and spectrally separated from the object of interest can be used to obtain an approximation of the point spread function. The crucial observation, corroborated by analytical calculations, is that the spectrally shifted point spread function is strongly correlated to a spatially scaled one. With the approximate point spread function thus obtained, the speckle-like pattern is deconvolved to produce a clear and sharp image of the object on a speckle-like background of low intensity.