Space Industry and Business News  
TECH SPACE
Recovering color images from scattered light
by Staff Writers
Durham NC (SPX) Jul 31, 2019

Researchers have created a method that takes light from colored numerals (top left) that has been scattered by a mostly opaque surface (top center) and uses its 'speckle' patterns and a coded aperture to reconstruct the image in five different frequencies (bottom row) before combining them into a final image (top right).

Engineers at Duke University have developed a method for extracting a color image from a single exposure of light scattered through a mostly opaque material. The technique has applications in a wide range of fields from healthcare to astronomy.

"Others have been able to reconstruct color images from scattered light, but those methods had to sacrifice spatial resolution or required prior characterization of the scatterer in advance, which frequently isn't possible," said Michael Gehm, associate professor of electrical and computer engineering at Duke. "But our approach avoids all those issues."

When light is scattered as it passes through a translucent material, the emerging pattern of "speckle" looks as random as static on a television screen with no signal. But it isn't random. Because the light coming from one point of an object travels a path very similar to that of the light coming from an adjacent point, the speckle pattern from each looks very much the same, just shifted slightly.

With enough images, astronomers used to use this "memory effect" phenomenon to create clearer images of the heavens through a turbulent atmosphere, as long as the objects being imaged were sufficiently compact.

While the technique fell out of favor with the development of adaptive optics, which do the same job by using adjustable mirrors to compensate for the scattering, it has recently became popular once again. Because modern cameras can record hundreds of millions of pixels at a time, only a single exposure is needed to make the statistics work.

While this approach can reconstruct a scattered image, it has limitations in the realm of color. The speckle patterns created by different wavelengths are typically impossible to disentangle from one another.

The new memory effect imaging approach developed by the authors Xiaohan Li, a PhD student in Gehm's lab, Joel Greenberg, associate research professor of electrical and computer engineering, and Gehm breaks through this limitation.

The trick is to use a coded aperture followed by a prism. A coded aperture is basically a filter that allows light to pass through some areas but not others in a specific pattern. After the speckle is "stamped" by the coded aperture, it passes through a prism that causes different frequencies of light to spread out from each other.

This causes the pattern from the coded aperture to shift slightly in relation to the image being captured by the detector. And the amount it shifts is directly related to the color of light passing through.

"This shift is small compared to the overall size of what's being imaged, and because our detector is not sensitive to color, it creates a messy combination," said Li. "But the shift is enough to give our algorithm a toehold to tease the individual speckle patterns apart from each color, and from that we can figure out what the object looks like for each color."

The researchers show that, by focusing on five spectral channels corresponding to violet, green and three shades of red, the technique can reconstruct a letter "H" full of nuanced pinks, yellows and blues. Outside of this difficult proof-of-principle, the researchers believe their approach could find applications in fields such as astronomy and healthcare.

In astronomy, the color content of the light coming from astronomical phenomena contains valuable information about its chemical composition, and speckle is often created as light is distorted by the atmosphere. Similarly in healthcare, color can tell researchers something about the molecular composition of what's being imaged, or it can be used to identify biomolecules that have been tagged with fluorescent markers.

"There are a lot of applications where people really want to know how much energy there is in specific spectral bands emitted from objects located behind opaque occlusions," said Greenberg. "We've shown that this approach can accomplish this goal across the visible spectrum. Knowing the aperture pattern and how much it shifts as a function of wavelength provides the key we need to disentangle the messy sum into separate channels."

The study appeared online on July 9 in the journal Optica.

Research Report: "Single shot multi-spectral imaging through a thin scatterer"


Related Links
Duke University
Space Technology News - Applications and Research


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


TECH SPACE
Lockheed contracted by Northrop Grumman for E-2D Hawkeye radars
Washington (UPI) Jul 25, 2019
Lockheed Martin has been contracted to produce APY-9 radars for the U.S. Navy's E-2D Advanced Hawkeye airborne early warning surveillance aircraft. The company is due to provide Northrop Grumman, manufacturer of the E-2D, 24 additional APY-9 radars for the aircraft over the next five years under a $600 million deal announced by Lockheed on Thursday. The deal follows a contract award in April for 24 more E-2D aircraft for the U.S. Navy. The ultra high frequency surveillance radar is desig ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TECH SPACE
Lockheed contracted by Northrop Grumman for E-2D Hawkeye radars

Finding alternatives to diamonds for drilling

Electronic chip mimics the brain to make memories in a flash

First of Two Van Allen Probes Spacecraft Ceases Operations

TECH SPACE
Newly established US Space Agency offers sneak peek at satellite layout

AEHF-5 encapsulated and prepared for launch

Corps begins fielding mobile satellite communication system

AFRL demonstrates world's first daytime free-space quantum communication enabled by adaptive optics

TECH SPACE
TECH SPACE
An AI technology to reveal the characteristics of animal behavior only from the trajectory

European Galileo satellite navigation system resumes Initial Services

Europe's Galileo GPS system back after six-day outage

Europe's GPS rival Galileo suffers outage

TECH SPACE
eFlyer 2 Prototype Begins New Flight Test Program with Siemens Production Motor

Pakistan's $125M request for F-16 support to go to U.S. Congress

US approves sales to support Pakistan's F-16s, India's C-17s

Space-enabled app for pilots takes to the skies

TECH SPACE
Scientists send light through 2D crystal layer in quantum computing leap

Speediest quantum operation 200 times faster than before

NIST's quantum logic clock returns to top performance

EU fines chipmaker Qualcomm 242 mn euros for 'predatory' pricing

TECH SPACE
Second laser boosts Aeolus power

Tracking Smoke From Fires to Improve Air Quality Forecasting

Commercial Space Ride Secured for NASA's New Air Pollution Sensor

Chaos theory produces map for predicting paths of particles emitted into the atmosphere

TECH SPACE
Insects replace pesticides in Spain's 'Sea of Plastic'

Earth's 2019 resources 'budget' spent by July 29: report

Fishing for plastic on Amsterdam's eco-friendly canal cruises

Sri Lanka says illegal UK waste offloaded to India, Dubai









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.