Sunday, September 02, 2012
Unknown
Scientists in Israel have created a camera that can see around corners, or through solid objects such as frosted glass, and skin. The most exciting facet of this innovation is that the camera uses natural light to perform the imaging — such as a lamp, or the Sun — and not lasers or X-rays.
Ori Katz, Eran Small, and Yaron Silberberg of the Weizmann Institute have shown that they can accurately resolve an object that’s hiding behind nearly opaque obstacles, or around a corner (or in another room, as long as the door’s open. In both cases, the light is scattered by the obstacle (the frosted glass, the corner wall), creating what appears to be white noise — but their camera can take these speckles of noise and enhance them “1000-fold” (the scientists’ words) to recreate the image with surprising accuracy.
The approach is surprisingly simple, and relies on a device called a spatial light modulator(SLM). Basically, when light bounces off an object, each part of that object changes the phase of light differently. An SLM is an array of pixels that can alter the phase of light passing through it, depending on the electrical current passing through each pixel. In this case, the scientists used a genetic optimization algorithm to modulate each pixel of the SLM until a sharp image is extracted from the white noise.
Ori Katz, Eran Small, and Yaron Silberberg of the Weizmann Institute have shown that they can accurately resolve an object that’s hiding behind nearly opaque obstacles, or around a corner (or in another room, as long as the door’s open. In both cases, the light is scattered by the obstacle (the frosted glass, the corner wall), creating what appears to be white noise — but their camera can take these speckles of noise and enhance them “1000-fold” (the scientists’ words) to recreate the image with surprising accuracy.
The approach is surprisingly simple, and relies on a device called a spatial light modulator(SLM). Basically, when light bounces off an object, each part of that object changes the phase of light differently. An SLM is an array of pixels that can alter the phase of light passing through it, depending on the electrical current passing through each pixel. In this case, the scientists used a genetic optimization algorithm to modulate each pixel of the SLM until a sharp image is extracted from the white noise.
In the image below, the first two images show the genetic algorithm’s ability to discern a single point of light in a mess of white noise; ‘c’ shows what the human eye would see, looking at the obstacle between the camera and object; and ‘d’ shows what this new camera can see through the obstacle.
Now, if you’re an avid follower of bleeding edge tech, you will probably remember a previous project by MIT — a femtosecond laser that could photograph objects at a trillion frames per second, or see around corners. The Israeli camera is significant because it uses incoherent light — a light bulb, daylight — and off-the-shelf hardware, while MIT’s laser approach is huge, unwieldy, and expensive.
Moving forward, the scientists hope that their SLM-based approach can play a significant role in medical imaging, where it is currently very hard to resolve details that are inside the brain or other organs. It’s also worth noting that MIT’s around-corners camera is laboratory-sized — but it sounds like the technology behind the Israeli design might fit into a conventional camera. If that doesn’t raise the eyebrows of wannabe superheroes and privacy advocates, I don’t know what will.
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