Scene setup: The scene is hidden behind a diffuser, with the scene being submerged in a scattering medium. Reconstructions of experimental data: Each column is a different scene. Top: images of the scenes behind the diffuser. Middle: Lindell and Wetzstein reconstructions (CDT). Bottom: our reconstructions using Phasor Fields. The higher frequency of CDT is related to the deconvolution to compensate scattering at the diffuser.

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Abstract

Non-line-of-sight (NLOS) imaging aims to reconstruct partially or completely occluded scenes. Recent approaches have demonstrated high-quality reconstructions of complex scenes with arbitrary reflectance, occlusions, and significant multi-path effects. However, previous works focused on surface scattering only, which reduces its generality in more challenging scenarios such as scenes submerged in scattering media. In this work, we investigate current state-of-the-art NLOS imaging methods based on Phasor Fields to reconstruct scenes submerged in scattering media. We empirically analyze the capability of Phasor Fields in reconstructing complex synthetic scenes submerged in thick scattering media. We also apply the method on real scenes, showing that it performs similarly as recent diffuse optical tomography methods.

Figures

Scene setup. The scene is hidden behind a diffuser, with the scene being submerged in a scattering medium.Simulated scenes. We use two simulated scenes: (Left) a single planar letter behind the diffuser (green), and (Right) a closed room with a shelf (red) at the back.
Reconstructions of the Z-LETTER scene. a) scene with no scattering media. b) reconstructions with scattering media of varying extinction µt (in m−1) and single scattering albedo α. c) reconstructions with scattering media of fixed extinction µt = 1 m−1, varying scattering albedo α, and phase function’s anisotropy g. Phasor Fields is able to reconstruct the scene even in the presence of highly scattering media.Reconstructions of the Z-LETTER scene in the presence of a scattering medium (µt = 1m−1 and α = 0.83 ) for increasing wavelength λ, with baseline λ0 = 4∆c and ∆c = 0.11m. Higher values of λ result into deeper penetration through the medium, at the cost of lower spatial.Reconstruction of the SHELF scene submerged in a medium of increasing density: µt = 0 (no media), µt = 1, and µt = 1.5. In all cases, the scattering albedo is α = 0.5.
Reconstructions of experimental data. Each column is a different scene. Top: images of the scenes behind the diffuser. Middle: Lindell and Wetzstein reconstructions (CDT). Bottom: our reconstructions using Phasor Fields. The higher frequency of CDT is related to the deconvolution to compensate scattering at the diffuser.

Bibtex

@article{Luesia:22,
  author = {Pablo Luesia and Miguel Crespo and Adrian Jarabo and Albert Redo-Sanchez},
  journal = {Opt. Lett.},
  keywords = {Diffuse optical tomography; Fourier optics; Imaging techniques; Multiple scattering; Scattering media; Spatial light modulators},
  number = {15},
  pages = {3796--3799},
  publisher = {Optica Publishing Group},
  title = {Non-line-of-sight imaging in the presence of scattering media using phasor fields},
  volume = {47},
  month = {Aug},
  year = {2022},
  url = {http://opg.optica.org/ol/abstract.cfm?URI=ol-47-15-3796},
  doi = {10.1364/OL.463296},
  abstract = {Non-line-of-sight (NLOS) imaging aims to reconstruct partially or completely occluded scenes. Recent approaches have demonstrated high-quality reconstructions of complex scenes with arbitrary reflectance, occlusions, and significant multi-path effects. However, previous works focused on surface scattering only, which reduces the generality in more challenging scenarios such as scenes submerged in scattering media. In this work, we investigate current state-of-the-art NLOS imaging methods based on phasor fields to reconstruct scenes submerged in scattering media. We empirically analyze the capability of phasor fields in reconstructing complex synthetic scenes submerged in thick scattering media. We also apply the method to real scenes, showing that it performs similarly to recent diffuse optical tomography methods.},
}