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3D pics made using visible light
Danny Rathjens writes "David Brady of the University of Illinois at Urbana-Champaign and colleagues combined two kinds of technology --
computed tomography (CT), which is used to scan the inside of the body, and interferometry, which makes it possible to see
an image without focusing on it, to make 3D pictures using visible light. "
[closeup of you, 10 years from now, you're at your desk maintaining the www.microsoft.mil website. Suddenly the phone rings..]
"Hello? .. Hi! What's up? .. .. uhh. .. hmm .. but .. .. .. Honey, she was only a few beams of light to me. Honest! .. .. No, no.. There's no need for the magnet.. Consider her deleted. Today. I know. Love you, bye.. *click*" .. Damn you David Brady! Damn you University of Illinois at Urbana-Champaign! aahhhh!
[you run out of your office and into the street where you are hit by a bus]
Moral: Good technology also has a bad side.
Actually, this is 3D, it's just not an image... it's a model that can then be rendered into an image that can be displayed in whatever method you like, including stereoscopic goggles if you're so inclined.
At least that's how I'm interpreting the complete lack of useful detail in the article...
This can only be considered good if you're on the same side as the SWAT team... and remember, the cops aren't necessarily the good guys... especially in, say, China...
I suspect the way it works, since they brought interferometry into it, is that they have a large number of small sensors (mini-cameras) scattered around and throughout the area being "filmed".
You'd have to apply algorithms similar to those used for CT to reconstruct the a 3d model from the data from the sensors, and interferometry comes in to play to compensate for the low spatial resolution of the individual sensors (as well as removing the need for them to be "focused" -- the more sensors, the sharper the detail).
Of course you'd still have problems with opacity, but with enough sensors scattered around that wouldn't be such an intractable problem. You just couldn't see the insides of stuff that you didn't have a window of some kind into and couldn't put a sensor inside of.
Stuff wouldn't need to be in full view of all of the sensors, either -- just, the fewer sensors that can see a feature, the more fuzzy ("out of focus") it'd be.
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DNA just wants to be free...
The group has a site at http://www.phs.uiuc.edu/4Is/
It includes a pretty spiffy mpeg of one of their scans. Cool.