Featured Research

from universities, journals, and other organizations

Single-pixel Camera Takes High-res Images: Engineers Use New Mathematics And Micro Mirrors In 'Multiplexed Camera'

Date:
October 2, 2006
Source:
Rice University
Summary:
Using new mathematics and a silicon chip covered with hundreds of thousands of bacterium-sized mirrors, Rice University engineers have designed a time-multiplexed camera that takes high-resolution images with a single photodiode. Today's battery-hungry megapixel cameras contain millions of photodiodes, but Rice's camera creates an image by capturing one pixel of light several thousands of times in succession. The research will be presented October 11 at Frontiers in Optics 2006 in Rochester, New York.

In a regular camera, a lens focuses light, for a brief instant, onto a piece of film or a photodiode array called a CCD. In the single-pixel camera, the image from the lens is shined onto a digital micromirror device, or DMD, and bounced from there though a second lens that focuses the light reflected by the DMD onto a single photodiode.
Credit: Image courtesy of Rice University

For all their ease and convenience, there are few things more wasteful than digital cameras. They're loaded with pricy microprocessors that chew through batteries at a breakneck pace, crunching millions of numbers per second in order to throw out up to 99 percent of the information flowing through the lens.

Related Articles


Using some new mathematics and a silicon chip covered with hundreds of thousands of mirrors the size of a single bacterium, engineers at Rice University have come up with a more efficient design. Unlike a one megapixel camera that captures one million points of light for every frame, Rice's camera creates an image by capturing just one point of light, or pixel, several thousands of times in rapid succession. The new mathematics comes into play in assembling the high-resolution image -- equal in quality to the one-megapixel image -- from the thousands of single-pixel snapshots.

The research will be presented Oct. 11 at the Optical Society of America's 90th annual meeting, Frontiers in Optics 2006, in Rochester, New York.

The oddest part about Rice's camera may be that it works best when the light from the scene under view is scattered at random and turned into noise that looks like television tuned to a dead channel.

"White noise is the key," said Richard Baraniuk, the Victor E. Cameron Professor of Electrical and Computer Engineering. "Thanks to some deep new mathematics developed just a couple of years ago, we're able to get a useful, coherent image out of the randomly scattered measurements."

Baraniuk's collaborator Kevin Kelly, assistant professor of electrical and computer engineering, built a working prototype camera using a digital micromirror device, or DMD, and a single photodiode, which turns light into electrical signals. Today's typical retail digital camera has millions of photodiodes, or megapixels, on a single chip.

DMDs, which are fabricated by Texas Instruments and today used primarily in digital televisions and projectors, are devices capable of converting digital information to light and vice versa. Built on a microchip chassis, a DMD is covered with tiny mirrors, each about the size of a microbe, that are capable of facing only two directions. They appear bright when facing one way and dark when facing the other, so when a computer views them, it sees them as 1's or 0's.

In a regular camera, a lens focuses light, for a brief instant, onto a piece of film or a photodiode array called a CCD. In the single-pixel camera, the image from the lens is shined onto the DMD and bounced from there though a second lens that focuses the light reflected by the DMD onto a single photodiode. The mirrors on the DMD are shuffled at random for each new sample. Each time the mirrors shift, a new pixel value is recorded by the photodiode. In effect, the lens and DMD do what the power-hungry microchip in the digital camera usually does; they compress the data from the larger picture into a more compact form. This is why the technique goes by the name "compressive sensing."

Today, it takes about five minutes to take a picture with Rice's prototype camera, which fills an entire corner of one of the table's in Kelly's laboratory. So far, only stationary objects have been photographed, but Kelly and Baraniuk say they should be able to adapt the "time-multiplexed" photographic technique to produce images similar to a home snapshot because the mirrors inside DMDs can alter their position millions of times per second. However, their initial efforts are aimed at developing the camera for scientific applications where digital photography is unavailable.

"For some wavelengths outside the visible spectrum, it's often too expensive to produce large arrays of detectors," Kelly said. "One of the beauties of our system is that it only requires one detector. We think this same methodology could be a real advantage in terahertz imaging and other areas."

The research is funded by the Defense Advanced Research Projects Agency, the Office of Naval Research, the National Science Foundation, Air Force Office of Scientific Research, and the Texas Instruments Leadership University Program.

For more information and images, visit: http://dsp.rice.edu/cs/cscamera and http://www.rice.edu/media/Camera.html


Story Source:

The above story is based on materials provided by Rice University. Note: Materials may be edited for content and length.


Cite This Page:

Rice University. "Single-pixel Camera Takes High-res Images: Engineers Use New Mathematics And Micro Mirrors In 'Multiplexed Camera'." ScienceDaily. ScienceDaily, 2 October 2006. <www.sciencedaily.com/releases/2006/10/061002154230.htm>.
Rice University. (2006, October 2). Single-pixel Camera Takes High-res Images: Engineers Use New Mathematics And Micro Mirrors In 'Multiplexed Camera'. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2006/10/061002154230.htm
Rice University. "Single-pixel Camera Takes High-res Images: Engineers Use New Mathematics And Micro Mirrors In 'Multiplexed Camera'." ScienceDaily. www.sciencedaily.com/releases/2006/10/061002154230.htm (accessed October 24, 2014).

Share This



More Computers & Math News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microsoft Riding High On Strong Surface, Cloud Performance

Microsoft Riding High On Strong Surface, Cloud Performance

Newsy (Oct. 24, 2014) — Microsoft's Q3 earnings showed its tablets and cloud services are really hitting their stride. Video provided by Newsy
Powered by NewsLook.com
The Best Apps to Organize Your Life

The Best Apps to Organize Your Life

Buzz60 (Oct. 23, 2014) — Need help organizing your bills, schedules and other things? Ko Im (@konakafe) has the best apps to help you stay on top of it all! Video provided by Buzz60
Powered by NewsLook.com
Nike And Apple Team Up To Create Wearable ... Something

Nike And Apple Team Up To Create Wearable ... Something

Newsy (Oct. 23, 2014) — For those looking for wearable tech that's significantly less nerdy than Google Glass, Nike CEO Mark Parker says don't worry, It's on the way. Video provided by Newsy
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins