Featured Research

from universities, journals, and other organizations

Quick, efficient chip cleans up common flaws in amateur photographs

Date:
February 19, 2013
Source:
Massachusetts Institute of Technology
Summary:
Smartphone snapshots could be instantly converted into professional-looking photographs with just the touch of a button, thanks to a new processor chip.

This image shows a setup of a demonstration system that integrates the processor with DDR2 memory and connects with a camera and a display through the USB interface. The system provides a platform for live computational photography.
Credit: MIT, Nathan Ickes, CC BY-NC-ND 3.0

Your smartphone snapshots could be instantly converted into professional-looking photographs with just the touch of a button, thanks to a processor chip developed at MIT.

The chip, built by a team at MIT's Microsystems Technology Laboratory, can perform tasks such as creating more realistic or enhanced lighting in a shot without destroying the scene's ambience, in just a fraction of a second. The technology could be integrated with any smartphone, tablet computer or digital camera.

Existing computational photography systems tend to be software applications that are installed onto cameras and smartphones. However, such systems consume substantial power, take a considerable amount of time to run, and require a fair amount of knowledge on the part of the user, says the paper's lead author, Rahul Rithe, a graduate student in MIT's Department of Electrical Engineering and Computer Science.

"We wanted to build a single chip that could perform multiple operations, consume significantly less power compared to doing the same job in software, and do it all in real time," Rithe says. He developed the chip with Anantha Chandrakasan, the Joseph F. and Nancy P. Keithley Professor of Electrical Engineering, fellow graduate student Priyanka Raina, research scientist Nathan Ickes and undergraduate Srikanth Tenneti.

One such task, known as High Dynamic Range (HDR) imaging, is designed to compensate for limitations on the range of brightness that can be recorded by existing digital cameras, to capture pictures that more accurately reflect the way we perceive the same scenes with our own eyes.

To do this, the chip's processor automatically takes three separate "low dynamic range" images with the camera: a normally exposed image, an overexposed image capturing details in the dark areas of the scene, and an underexposed image capturing details in the bright areas. It then merges them to create one image capturing the entire range of brightness in the scene, Rithe says.

Software-based systems typically take several seconds to perform this operation, while the chip can do it in a few hundred milliseconds on a 10-megapixel image. This means it is even fast enough to apply to video, Ickes says. The chip consumes dramatically less power than existing CPUs and GPUs while performing the operation, he adds.

Another task the chip can carry out is to enhance the lighting in a darkened scene more realistically than conventional flash photography. "Typically when taking pictures in a low-light situation, if we don't use flash on the camera we get images that are pretty dark and noisy, and if we do use the flash we get bright images but with harsh lighting, and the ambience created by the natural lighting in the room is lost," Rithe says.

So in this instance the processor takes two images, one with a flash and one without. It then splits both into a base layer, containing just the large-scale features within the shot, and a detailed layer. Finally, it merges the two images, preserving the natural ambience from the base layer of the nonflash shot, while extracting the details from the picture taken with the flash.

To remove unwanted features from the image, such as noise -- the unexpected variations in color or brightness created by digital cameras -- the system blurs any undesired pixel with its surrounding neighbors, so that it matches those around it. In conventional filtering, however, this means even those pixels at the edges of objects are also blurred, which results in a less detailed image.

But by using what is called a bilateral filter, the researchers are able to preserve these outlines, Rithe says. That is because bilateral filters will only blur pixels with their neighbors if they have been assigned a similar brightness value. Since any objects within the image are likely to have a very different level of brightness than that of their background, this prevents the system from blurring across any edges, he says.

To perform each of these tasks, the chip's processing unit uses a method of organizing and storing data called a bilateral grid. The image is first divided into smaller blocks. For each block, a histogram is then created. This results in a 3-D representation of the image, with the x and y axes representing the position of the block, and the brightness histogram representing the third dimension.

This makes it easy for the filter to avoid blurring across edges, since pixels with different brightness levels are separated in this third axis in the grid structure, no matter how close together they are in the image itself.

The algorithms implemented on the chip are inspired by the computational photography work of associate professor of computer science and engineering Fredo Durand and Bill Freeman, a professor of computer science and engineering in MIT's Computer Science and Artificial Intelligence Laboratory. With the aid of Taiwanese semiconductor manufacturer TSMC's University Shuttle Program, the researchers have already built a working prototype of the chip using 40-nanometer CMOS technology, and integrated it into a camera and display. They will be presenting their chip at the International Solid-State Circuits Conference in San Francisco in February.

The work was funded by the Foxconn Technology Group, based in Taiwan.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Helen Knight. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts Institute of Technology. "Quick, efficient chip cleans up common flaws in amateur photographs." ScienceDaily. ScienceDaily, 19 February 2013. <www.sciencedaily.com/releases/2013/02/130219121218.htm>.
Massachusetts Institute of Technology. (2013, February 19). Quick, efficient chip cleans up common flaws in amateur photographs. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/02/130219121218.htm
Massachusetts Institute of Technology. "Quick, efficient chip cleans up common flaws in amateur photographs." ScienceDaily. www.sciencedaily.com/releases/2013/02/130219121218.htm (accessed April 23, 2014).

Share This



More Computers & Math News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Monkeys Are Better At Math Than We Thought, Study Shows

Monkeys Are Better At Math Than We Thought, Study Shows

Newsy (Apr. 23, 2014) A Harvard University study suggests monkeys can use symbols to perform basic math calculations. Video provided by Newsy
Powered by NewsLook.com
High Court to Hear Dispute of TV Over Internet

High Court to Hear Dispute of TV Over Internet

AP (Apr. 22, 2014) The future of Aereo, an online service that provides over-the-air TV channels, hinges on a battle with broadcasters that goes before the U.S. Supreme Court on Tuesday. (April 22) Video provided by AP
Powered by NewsLook.com
Aereo Takes on Broadcast TV Titans in Supreme Court Today

Aereo Takes on Broadcast TV Titans in Supreme Court Today

TheStreet (Apr. 22, 2014) Aereo heads to the Supreme Court today to fight for its right to stream broadcast TV over the Internet -- against broadcasters who say the start-up infringes upon copyright law. TheStreet Deputy Managing Editor Leon Lazaroff explains the importance of the case in the TV industry and details what the outcome of it could mean for broadcasters and for cloud storage services -- as Aereo allows its subscribers to not just watch live TV shows but also store content to a DVR in the cloud. Video provided by TheStreet
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
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:
from the past week

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