A Camera That Can See Through Walls
Camera Culture Research Group's Time-of-Flight Microwave Camera
Modern cameras cannot see through fog, in the dark, or through walls, making the development of driverless vehicles or better search and rescue equipment difficult. Where visible light fails, radio waves can easily penetrate these obstructions; but, radar imaging devices are complex, low resolution, and unable to image certain geometries and angled surfaces. To address this, the Media Lab’s Camera Culture group has taken a camera-like approach to microwave imaging, resulting in a simpler camera architecture that can capture fuller 3D images through walls.
Where visible light has a wavelength between 390nm and 700nm, the Camera Culture camera sees between 2.5cm and 4cm (much larger). While classical radar imaging devices can perform these tasks, they do so with highly complex systems that are out of the reach of the consumer.
This new radar imaging architecture makes imaging at long wavelengths more accessible, while enabling higher resolution imaging; keeping all electronics in a small 10” x 10” space; requiring fewer detectors; providing better detection of mirror-like surfaces; and providing both multispectral and time-resolved imaging (capturing microwaves in flight).
Unbounded High Dynamic Range Photography Using a Modulo Camera
Camera Culture group research may be the beginning of the end for over-saturated images
Trying to take pictures in the dark or through a window is difficult for professional photographers and everyday people alike. A group of researchers at MIT have proposed a camera that can take a perfect picture, no matter what the lighting contrast is. Called a “modulo camera,” this camera is designed to never overexpose an image, enabling high dynamic range photography. This achievement was awarded the best paper runner-up at the 2015 International Conference on Computational Photography.
High dynamic range (HDR) imaging is a method that allows both very bright and very dim light sources to be pictured in a single image with no loss in quality. HDR cameras have been created before, but conventional HDR cameras use multiple normal images to create one final HDR image. This means that if the camera is shaking, or if the image is of a moving target, the HDR technique does not work. However, the modulo camera, created in a collaboration between the Media Lab's Camera Culture group, MIT Lincoln Lab, and Singapore University of Technology and Design, only requires one shot to create an HDR image. This not only allows HDR photos to be taken free of blur, but also allows for the possibility of HDR video.
Conventional camera sensors will get “full," or saturated, after receiving an excess amount of light. This is because conventional camera sensors have a limited “well capacity,” or a limited amount of light the sensors can take in before they overflow. The modulo camera solves the saturation problem by resetting the sensor capacitors whenever the "well" gets full, and uses an inverse modulo algorithm to calculate how much light the reset sensors took in. This algorithm recovers a much larger dynamic range. For example, if a certain camera sensor can record eight bits of information, then when those eight bits are filled, the capacitor will be reset to zero. The number of resets is recovered by the algorithm, which then calculates the relative brightness of each area of the photo.
There are numerous uses for this technology. No more will photographers or even ordinary people have to fumble with aperture size and exposure length. The algorithm would enable people simply to click the camera button and let the computer deal with exposure problems. The modulo camera can potentially transform the way everyday photography works.
Furthermore, cameras serve as visual input for robots. Clarity in all lighting conditions is crucial to robotic vision. However, good lighting cannot always be guaranteed. When a driverless car drives into a tunnel, an ordinary camera goes blind: the exit ahead is bright, and the surroundings are dark, so the camera cannot see both inside the tunnel and out of it. A real-time HDR camera could guarantee safety in these conditions. The list of real-world applications goes on: laser image speckling, astronomy, and any field that deals with sources of both bright and low light could be transformed by the modulo camera technology.
New Faculty Publication
Why Information Grows:
The Evolution of Order, From Atoms to Economies
An interdisciplinary theorist, Cesar Hidalgo, the Macro Connections group leader at the MIT Media Lab, invites us to understand the economy in an entirely different way.
In the wake of the 2008 recession, an outpouring of books—for example, J.K. Galbraith’s The End of Normal: The Great Crisis and the Future of Growth (2014)—has criticized the insularity of economists and their unwillingness to expand the discipline’s perspective. Now comes Hidalgo (co-author: The Atlas of Economic Complexity: Mapping Paths to Prosperity (2014) with a lens wide open. Drawing insights from chemistry, history, biology, anthropology, economics, and sociology, he urges us to see economic growth as “the social manifestation of the growth of information,” “information” defined not as meaning but rather as physical order. Hidalgo’s nontraditional approach requires careful definition of a number of words—e.g., “knowledge” and “knowhow,” “entropy” and “computation”—and occasionally a new vocabulary (the awkward but useful “personbyte” and “firmbyte”). In the world as Hidalgo sees it, a Bugatti is “an uncommon configuration of matter” whose value (new vs. crashed) depends entirely on the configuration of atoms. As he progresses from atoms to economies, Hidalgo offers a variety of startling insights about physical objects as the embodiment of information; about whirlpools as “information rich”; about markets as incarnations not of riches but of wisdom; about the limits of once-productive networks like Ford’s River Rouge; and about the perilous consequences of a social group’s isolation. He explains why the human capacity to crystalize wisdom is “geographically speckled”; why modern products no longer remain strongly associated with particular regions (Champagne with France, clocks with Switzerland); and why a trip through the birth canal is akin to time travel.
Some readers, perhaps economists especially, will construe Hidalgo’s widely allusive musings as dotty dispatches from Jonathan Swift’s Laputa; others will delight in his novel, holistic take on the dismal science.
6/8, 12:20pm: Cesar Hidalgo interviewed by Geoff Mulgan
6/4, 1:00pm: Cesar Hidalgo speaks at RSA House
7/2, 7pm: César Hidalgo at Harvard Book Store