Researchers use light projector and single-pixel detectors to create 3-D images

May 17, 2013 by Bob Yirka weblog

(Phys.org) —Researchers from the University of Glasgow and the University of Cambridge have devised a unique method of capturing three-dimensional images. As described in a paper published in the journal Science, they used an ordinary light projector, four single-pixel photodetectors, an analog-to-digital converter, and a computer to capture 3-D images of a mannequin head.

The idea is based on the concept of ghost imaging where paired light sources, such as a split laser beam, are used to create 3-D images. Prior efforts have involved shooting a target with one part of the split beam, then capturing the reflected light with a photodetector. The other part of the beam is recorded by a traditional camera. In this new effort, the researchers took a much more pragmatic approach—they accomplished the same thing using simpler equipment.

To create the 3-D image, the researchers set up a light projector—the same kind used for viewing slides on a screen—with the light projected onto a mannequin head. Next, they placed a transparent screen capable of displaying light-blocking speckle patterns (generated by the computer) between the projector and the mannequin head. Light able to pass through the speckle pattern would eventually strike the mannequin and bounce off. Four single-pixel photodetectors were set up to capture the bounced light—one each above, below and to each side of the projector. The photodectectors were connected to an analog-to-digital converter which sent results to the computer. Once everything was in place, the researchers caused the computer to send different speckle patterns to the screen while the photodetectors captured the reflected light. Each pass allowed the computer to capture more information. As the total number of speckle patterns reached a million, individual 2-D images emerged—each one based on data from a single . Software on the then used the four 2-D to create a single 3-D image.

How such a system might be used is still up for debate, as some issues still need to be worked out. The slow refresh rate, for example, means it takes half an hour to create one image. The researchers are confident they can refine the design, however, to speed up the process. Once that happens, they suggest, their imaging system might be useful for detecting gas fields, building medical systems or catching terrorists at airports.

Original press release.

Explore further: Our new anti-earthquake technology could protect cities from destruction

More information: Science 17 May 2013: Vol. 340 no. 6134 pp. 844-847 DOI: 10.1126/science.1234454

Related Stories

Diffused light control can project in fully lit room

Apr 20, 2011

(PhysOrg.com) -- Researchers at the Uchida Research Laboratory at Tohoku University, have created a high visibility projector screen that works on the principle of Diffused Light Control (DLC). The long and ...

Recommended for you

Focused energy of lasers breaks microscopic adhesion

Jul 02, 2015

Small objects tend to cling to everything. It's why parents dread hosting parties that involve confetti. It's why glitter is fun for crafts—until it finds its way onto everything else you touch.

Insect decoys could protect ash trees

Jul 02, 2015

Emerald ash borers have no trouble reproducing themselves as they have now spread through half the United States, but duplicating effective emerald ash borer decoys is not quite as easy. Now, engineers have ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

jscroft
1 / 5 (2) May 17, 2013
Smart dust. What if you have ten thousand networked cameras, each one capturing a single pixel?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.