Soldiers’ and spies’ ability to capture images in the dark may be getting a boost from the school of engineering at Massachusetts Institute of Technology.
An algorithm developed at the school’s Research Laboratory of Electronics enables a camera firing low-intensity pulses of visible laser light into a near-total dark environment to create 3D images of objects present, according to the journal Science.
The camera works much like the light detection and range scanners employed by surveyors to gauge distances – measurements calculated by the time it takes for reflected photons to get back to the scanner. The camera used by the MIT team fires a pulse at a given location until a single reflected photon is recorded by a detector, with each illuminated spot resulting in a pixel in the image being created.
In addition, the team led by electrical engineer Ahmed Kirmani, developed an algorithm that actually factors in correlations between the illuminated photon and the physics of low-light measurements, Science reported.
“We introduce a low-flux imaging technique, called first-photon imaging, which is a computational imager that exploits spatial correlations found in real-world scenes and the physics of low-flux measurements,” the team states in Science, which published the study Nov. 29 online. “Our technique recovers 3D structure and reflectivity from the first detected photon at each pixel.”
“We didn’t invent a new laser or a new detector,” Kirmani told the magazine, but developed and applied their imaging algorithm so that it could be used with standard, off-the-shelf photon detectors. Kirmani, a doctoral candidate in electrical engineering and computer science at MIT, previously invented compact, low-power 3D cameras that MIT officials said could “usher in new forms of human-machine interaction, automation and medical imaging.”
According to MITnews, the Kirmani team’s system for capturing 3D images in the dark produces results of a quality that a conventional imaging system would require 900 times the light to create.