Computing the amounts of light arriving from different directions enables a diffusely reflecting surface to play the part of a mirror in a periscope—that is, perform non-line-of-sight imaging around an obstruction. Because computational periscopy has so far depended on light-travel distances being proportional to the times of flight, it has mostly been performed with expensive, specialized ultrafast optical systems. Here we introduce a two-dimensional computational periscopy technique that requires only a single photograph captured with an ordinary digital camera. Our technique recovers the position of an opaque object and the scene behind (but not completely obscured by) the object, when both the object and scene are outside the line of sight of the camera, without requiring controlled or time-varying illumination. Such recovery is based on the visible penumbra of the opaque object having a linear dependence on the hidden scene that can be modelled through ray optics. Non-line-of-sight imaging using inexpensive, ubiquitous equipment may have considerable value in monitoring hazardous environments, navigation and detecting hidden adversaries.
Computational Periscopy with an Ordinary Digital Camera
Charles Saunders, John Murray-Bruce, and Vivek K Goyal,
Nature, vol. 565, pp. 472-475, 24 Jan 2019.
Shadows used to peer around corners
Martin Laurenzis (invited commentary),
Nature, vol. 565, pp. 435-436, 24 Jan 2019.
Code and data
How an ordinary camera can see around corners,
Davide Castelvecchi, January 23, 2019.
The Economist (print issue 24 Jan 2019),
A camera that can see round corners,
January 24, 2019.
A Simple Camera and an Algorithm Let You See around Corners,
Jeff Hecht, January 23, 2019.
Spying around corners just got easier,
Natalie Parletta, January 24, 2019.
The Daily Free Press,
BU professor develops camera that can see around corners,
Andy Vo and Susannah Sudborough, January 27, 2019.
Spooky Algorithm Sees Around Corners by Analyzing Shadows,
Dan Robitzski, January 25, 2019.
The 5 Coolest Things On Earth This Week,
Sam Worley, January 23, 2019.
Program allows ordinary digital camera to see round corners,
Ian Sample, January 23, 2019.
How to See Around Corners with a Digital Camera,
Marcus Woo, January 23, 2019.
La cámara digital que puede tomar imágenes de objetos escondidos,
Amado Herrero, January 23, 2019.
Este algoritmo permitirá a la cámara de tu smartphone ver detrás de las esquinas,
Victor Román, January 24, 2019.
Algorithm that can see around corners could help autonomous cars,
Yvaine Ye, January 23, 2019.
Using Just a Digital Camera, a New Method Lets Scientists See Around Corners,
Kendra Redmond, January 23, 2019.
Shadowy algorithm allows digital camera to see round corners,
Sam Jarman, January 25, 2019.
This incredible new technique allows us to see around corners in photographs!,
Adrian Pennington, January 31, 2019.
This Not-at-All-Creepy New Computer Program Lets Any Camera See Around Corners,
David Nield, January 25, 2019.
Ordinary cameras can now photograph out-of-sight objects,
Maria Temming, January 23, 2019.
Scientists Used an Ordinary Digital Camera to Peer Around a Corner,
Jane Recker, January 23, 2019.
Algorithm allows cameras to see around corners,
February 12, 2019.
Your Camera Could Soon See Around Corners,
Jack Turner, January 25, 2019.
Soldiers could see round corners using digital cameras with new technology,
Sarah Knapton, January 23, 2019.
Times of London,
Camera that could help your car see around corners,
Tom Whipple, January 24, 2019.
The Wilson Leader Bulletin,
Military dream come true – the camera looks around the corner,
Teodora Torrendo, January 26, 2019.
A Digital Camera That Can Help You See Beyond Walls,
Sarah Iqbal, February 15, 2019.
Scientists Reconstruct an Object by Photographing its Shadow,
Sophia Chen, January 23, 2019.
Seeing around Corners,
January 23, 2019.
Can Technology Eliminate Blind Spots?,
January 23, 2019.
BBC Radio 5 Live, January 25, 2019.
talkRADIO UK, January 27, 2019.
Digital camera sees around corners by guessing what’s lurking behind,
Jon Cartwright, May 17, 2019.
Seeing around corners: How to decipher shadows to see the invisible,
Jon Cartwright, November 6, 2019.
Peeking Around the Corner,
Tanita Hecking, July 2020.
Additional commentary, repostings, and translations online at many sites including: ABC News, Futurity, R&D Magazine, le Scienze.
This work was supported by the Defense Advanced Research Projects Agency (DARPA) REVEAL Program contract number HR0011-16-C-0030.