Efficient Non-Line-of-Sight Imaging from Transient Sinograms

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 12352)


Non-line-of-sight (NLOS) imaging techniques use light that diffusely reflects off of visible surfaces (e.g., walls) to see around corners. One approach involves using pulsed lasers and ultrafast sensors to measure the travel time of multiply scattered light. Unlike existing NLOS techniques that generally require densely raster scanning points across the entirety of a relay wall, we explore a more efficient form of NLOS scanning that reduces both acquisition times and computational requirements. We propose a circular and confocal non-line-of-sight (\(\text {C}^2\text {NLOS}\)) scan that involves illuminating and imaging a common point, and scanning this point in a circular path along a wall. We observe that (1) these \(\text {C}^2\text {NLOS}\) measurements consist of a superposition of sinusoids, which we refer to as a transient sinogram, (2) there exists computationally efficient reconstruction procedures that transform these sinusoidal measurements into 3D positions of hidden scatterers or NLOS images of hidden objects, and (3) despite operating on an order of magnitude fewer measurements than previous approaches, these \(\text {C}^2\text {NLOS}\) scans provide sufficient information about the hidden scene to solve these different NLOS imaging tasks. We show results from both simulated and real \(\text {C}^2\text {NLOS}\) scans (Project page:


Computational imaging Non-line-of-sight imaging 



We thank Ioannis Gkioulekas for helpful discussions and feedback on this work. M. Isogawa is supported by NTT Corporation. M. O’Toole is supported by the DARPA REVEAL program.

Supplementary material

Supplementary material 1 (mp4 42570 KB)

504444_1_En_12_MOESM2_ESM.pdf (7.6 mb)
Supplementary material 2 (pdf 7782 KB)


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© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Carnegie Mellon UniversityPittsburghUSA

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