Laser Camera Can See Around Corners

Hugh Pickens writes "Researchers at MIT have developed a laser camera that can 'see' around corners and take pictures of a scene not in its direct line of sight. The camera system fires extremely short bursts of light that can reflect off one object, such as the open door of a room, and then off a second object inside the room before reflecting back to the first object and being captured by the camera, after which algorithms can use the information to reconstruct the hidden scene exploiting the fact that it is possible to capture light at extremely short time scales, about one quadrillionth of a second. By continuously gathering light and computing the time and distance that each pixel has traveled, the camera creates a '3D time-image' of the scene it can't directly see. 'It's like having X-ray vision without the X-rays,' says Professor Ramesh Raskar. 'We're going around the problem rather than going through it.'"

Comments

Re:No images

[goldaryn]

http://www.taylorsgardenbuildings.co.uk/store/images/d_9979.jpg

Re:No images

[HateBreeder]

Try this:
http://www.bbc.co.uk/news/technology-11544037

TSA can look up your trousers

[ciaran_o_riordan]

Great, so instead of x-raying or groping travellers, maybe TSA can subtly take a few snaps up the leg of people's trousers and down the top of your t-shirt :-)

http://www.prisonplanet.com/tsa-now-putting-hands-down-fliers-pants.html

http://www.wired.com/threatlevel/2010/11/tsa-investigating-passenger/

It's like having X-ray vision without the X-rays

[Anonymous Coward]

It's like having X-ray vision without the X-rays...

So it's like having vision?

Here's a link to the actual MIT site...

[Anonymous Coward]

http://web.media.mit.edu/~raskar/femto/

Enough of Slashdot's SEO link farming spammy shit. Here's what you want to read, unless you like your science news dumbed down to a third grade level.

Re:Here's a link to the actual MIT site...

[icebraining]

[quote]Light travels 1 foot/nanosecond(...)[/quote]
How much is that in Libraries of Congress?

Really, foots per nanosecond? I thought it was a scientific experiment.

C is exactly 299792458 ms.

Re:Here's a link to the actual MIT site...

[argStyopa]

"C is exactly 299792458 ms" ...which is precisely as arbitrary, if more widely accepted, than cubits per moon phase.

I swear, metric evangelism is becoming more rabid every week. Oh wait, I'm sorry, it's becoming more rabid every 2/100ths of a year.

Hmmmm...

[tygerstripes]

The process has to be incredibly time-sensitive in order to work, and the imaging process has to subtract ambient light in order to obtain the reflected-laser data. This ambient-light recording has to happen at a different time to when the laser is fired, so variable-light conditions or the lack of an incredibly steady camera, image object and reflective surface will make it basically impossible to render the image.

I absolutely love the concept. I just think that the nay-sayers whom Professor Raskar claims to be defeating were correct. It might not be theoretically impossible, but the practical limitations are so severe that I don't envisage them being "engineered" away - and if they are, such phenomenal engineering accomplishments would make this application appear trivial in comparison with the other things we could do.

Re:Hmmmm...

[Lluc]

Given that he's using a femtosecond laser and some kind of exotic "streak" camera, I think he has to essentially raster scan the area he's imaging "around the corner". I doubt the ambient lighting or the scene itself will change in a femtosecond, but the raster-scanner better move pretty fast! A fast raster-scanner might be solvable, even. I think the biggest problem he's going to have is dealing with a non-sparse scene. I think this works well for simple geometries, but once he starts dealing with a really complicated scene, there will be too many possibilities to sort out for each given measurement. (Too many variables!)
I wonder how many real scientific "nay-sayers" he really had to deal with -- in his publication he states that this project is an extension of LIDAR work that was done 10+ years ago. I think it's very cool academic research, but I also think that MIT Media Lab *loves* to hype the every-day/year cool engineering project as though it's a complete world changer.

And guess what

[Rosco P. Coltrane]

The first customer will either be the TSA or some branch of the military.

High-tech companies would invent anything that would sell to any agency vaguely related to counter-terrorism or warfare these days. If they poured a tenth of the resources they spent developing this kind of devices into finding solutions to the world's real problems, we'd all be cancer-free and solar-powered by now...

Re:And guess what

[Pieroxy]

...we'd all be cancer-free and solar-powered by now...

and under the reign of the Queen of England.

hearsay

[ei4anb]

Slashdot says that UPI.com said that physorg.com said that Tech Radar said that MIT said that there is an interesting paper at http://dspace.mit.edu/bitstream/handle/1721.1/58402/656284100.pdf?sequence=1 and the BBC went to learn more, conduct an interview and take photos http://www.bbc.co.uk/news/technology-11544037

Re:No images

[TheLink]

Here's a related video: http://www.youtube.com/watch?v=KUFkb0d1kbU

Blade Runner

[Digital Vomit]

Now that scene in Blade Runner is making more sense...

Re:How Fast Are Pixels?

[natehoy]

Do pixels travel at the speed of light?

Depends on your refresh rate.

I wonder what it feels like to get hit by a pixel.

Depends on the resolution, and of course the refresh rate which determines velocity. Set a 24" monitor to 1x1 resolution with a 100MHz refresh rate, and it hurts like hell. Set it ag 32,700 x 27,000, not so much, unless you get hit by all of the pixels or the pixel you are hit by is at a very high refresh rate.

Are they larger or smaller than a photon?

Larger, silly, they're made of pixel dust.

Re:No images

[TheLink]

I actually find the eye-test thing in the later part more interesting.

A "looking round the corner" device is likely to be very expensive and so only useful to a few people.