Slashdot Mirror
Algorithm Reveals Objects Hidden Behind Other Things In Camera Phone Images
KentuckyFC writes "Imaging is undergoing a quiet revolution at the moment thanks to various new techniques for extracting data from images. Now physicists have worked out how to create an image of an object hidden behind a translucent material using little more than an ordinary smartphone and some clever data processing. The team placed objects behind materials that scatter light such as onion skin, frosted glass and chicken breast tissue. They photographed them using a Nokia Lumina 1020 smartphone, with a 41 megapixel sensor. To the naked eye, the resulting images look like random speckle. But by treating the data from each pixel separately and looking for correlations between pixels, the team was able to produce images of the hidden objects. They even photographed light scattered off a white wall and recovered an image of the reflected scene--a technique that effectively looks round corners. The new technique has applications in areas such as surveillance and medical imaging."
I am sold!
It is often not obvious which is which. So save your "enhance!" jokes.
We are rapidly approaching the glorious day when we can announce the elusive 'Victoria's Secret Clothing Filter' app.
Pretending this is my office full of bitter coworkers..
I remember seeing a conference presentation a few years ago that promised to see through clothing using image processing (like the scanners at the airport, except cheap and accessible to everyone).
Luckily (I would think), this didn't work out in practice.
I expect this method won't either.
You mean like the frosted glass commonly used for bathroom windows and shower doors? I see this as being a form of image processing that will rapidly be perfected.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
It is a Nokia LUMIA not Lumina.
"Lumina" is how stupid customers call the phones they own without even bothering to read their names (no wonder they cannot use whatever runs on it).
Sincerely,
A guy who works in the customer service and has to deal with Lumias all the time
You have a heck of lot of information to work with.
Didn't RFA the phrase "using little more than an ordinary smartphone", that would be 5 Meg Pix here, and damn impressive.
It is object behind a translucent screen. It does some AI based image sharpening. It is not the classic tank behind a tree. Nor reconstructing a face partially hidden by faces or hoodies etc.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Tits or it never happened.
But this is far more entertaining: http://media.moronail.net/imag...
"a technique that effectively looks round corners"
What does that mean? Obviously you meant "a technique that effectively looks around corners" but you were too lazy.
This will be obviously used for porn. Algorithm that lets us see partially censored boobs!
Some of us are interested in the theory, not to mention that both the article and the paper contain actual images. It's not the fault of the authors that you didn't bother to read them through.
This is an impressive step forward in image processing - while reconstructing an image from diffuse light seemed plausible in theory, figuring out how to do it in practice is a hard problem. These guys deserve some respect.
That's because they were hidden. You have to use your phone to see them.
Sounds like an offshoot of these guys .
If you could reason with religious people, there would be no religious people
Theorize all you want. Pics or it didnt happen.
No, you see all of the images from the paper right up at the top. The kicker is that it can only do monochrome. So your x-ray voyeur shots will only work for girls and boys wearing full-body paint under their clothes. Or maybe you can illuminate them with lasers. I'm sure nobody will notice.
An algorithm for perceiving objects hidden behind other objects could...enable even men to find things in the refrigerator!
Doesn't anybody actually read anything? If you follow the last link in the story, and click 'PDF Only' from there, you can view the paper including sample images.
That they don't really understand what a pixel is.
I'm not disputing the awesomeness of this, just saying that the article is awful. It's some kind of JavaScript powered blog that doesn't scroll properly.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
How could you possibly do this experiment without trying it through the frosted glass of a shower door with a naked person on the other side?
-Styopa
http://youtu.be/JMIHNiR3CP8
The Official Site of 1337 Pwnage
I don't even want to know the intended practical application of the chicken skin. Just don't tell T-S-A about it :-)
Table-ized A.I.
It should also be useful in situations where lenses are hard to use. The most expensive and problematic part of the Hubble Space Telescope, for example, was its lens.
Um, no. The most expensive and problematic part of the Hubble Space Telescope was the primary mirror of its Ritchey–Chrétien reflector type telescope, although I suppose a layman could mistake that for a lense.
Who decided these were a good idea? Even the BBC did one a few days ago.
systemd is Roko's Basilisk.
Doesn't have to be *visible* layers, and then you can just colorize.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
What have I got in my pocket?
The term is deconvolution.
It's been around for a LONG time. It's almost certainly already been used to spy on you by more than one country.
No, you see all of the images from the paper right up at the top. The kicker is that it can only do monochrome. So your x-ray voyeur shots will only work for girls and boys wearing full-body paint under their clothes. Or maybe you can illuminate them with lasers. I'm sure nobody will notice.
You can use a filter at the camera. The paper says as much. However, getting your hottie to stand naked very close to a very thin translucent screen while you film from the other side hoping to get a distorted outline sounds pointless.
I can see how this would be useful for everyday photography. Reducing atmospheric interference like haze and mirage, etc. Pretty cool technology.
The Lumia (not "Lumina", lol...) 1020 isn't *that* expensive. Its sensor is top-notch for a smartphone today, but it was only a few years ago that 5MPx was considered excellent in a phone and only professional gear (typically tens of thousands of dollars) could hit 40+MPx. Technology marches on. Today, a low-end smartphone typically has a 5MPx sensor. Assuming CCDs and/or CMOS chips follow Moore's Law (they might not, but I suspect they do, or something close to it) in about six years even cheap phones will have 40MPx camera sensors. This doesn't sound like too early to start working on the implications of that sort of capability at all...
There's no place I could be, since I've found Serenity...
See Blade Runner Esper machine, which was parodied on Red Dwarf.
What browser are you using? I just tried in:
- opera on windows
- chrome on windows
- ff on windows
- IE on windows
- opera mini on ios
- safari on ios
and the scrolling is fine in all of them. And I do have complicated setups with lots of extensions and stuff...
Really? It's hard to see a tank behind a tree? Bloody big tree!
Or you are just really close to the tree.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
I don't claim to be an imaging expert, but a few odd details about the experimental method jumped out at me. It's been known for some time now that diffusive and other scene-perturbing objects (e.g. grossly distorting 'lenses' such as a Coke bottle) can be nullified using a structured light technique to characterize and effectively 'undo' the perturber. A simple structured light example is to replace the light source with a DLP projector and take multiple images with only one pixel illuminated at a time. More clever implementations can replace the single pixels with speckle patterns, zebra stripes, etc., and replace the 2D imager with a single-pixel photocell. Other neat tricks can then be performed such as reconstructing the image from the POV of the light source rather than the imaging device.
The experimentals shown in this paper all seem to have two things in common: 1) the "object" in each case is a backlit, 2D binary pattern on a transparency film or similar, with a relatively small illuminated area, and 2) an extremely narrowband (laser, actually) light source is used. The paper does mention several times that the light source is non-coherent, but it is a laser under the hood. This explains the numerous references to "speckle" in the images, which may leave most readers scratching their heads since things don't normally speckle when looked at through a slice of onion under ordinary light. Speckling is a laser (de)coherence phenomenon where the rays are put slightly out of coherence so as to interfere constructively and destructively.
These things suggest to me that while the paper is definitely interesting, there is no need to worry about the neighbors snapping passable nudes through your shower door or Feds cataloging your grow farm via pictures of a blank wall through your window. This sounds more like a modest extension to what's already been done stirring coherent and structured-light in a pot with convolution and autocorrellation methods.
Since the coherence length of cheap semiconductor lasers (e.g. laser pointers) can be on the order of 1mm or less, it's possible to call even a straight-up laserbeam "non-coherent narrowband light" with a somewhat straight face. Likewise, the quasi-point-sources created using a sparse geometric 2D aperture in transparency film, backlight by the aforementioned source, is pretty close to structured light for practical purposes. The takeaway message is these are very special lighting and "scene" conditions that are not representative of everyday photographic circumstances. So not to worry just yet :-)
Caveat Emptor is not a business model.
This is an impressive step forward in image processing - while reconstructing an image from diffuse light seemed plausible in theory, figuring out how to do it in practice is a hard problem. These guys deserve some respect.
Well, some respect, but it's hardly cutting edge or even very new. Maybe for physicists, but CS was ahead.
Kohonen described the basics of correlated reconstruction back in the 1980s.
There were videos of reading the backs of cards from diffuse lighting by the early 2000s. Admitted using some cheats like controlling the light source, but not awful compared to this paper that restricts the color.
By the late 2000s, the ideas were pretty common and computationally feasible. I even wrote a few POCs myself while working on somewhat related optical stuff.
Maybe for physicists, but CS was ahead.
No, we've been using the same principles for dealing all sorts of not so pretty instrument functions and such, although I don't know of anyone that bothered to throw it into an app that can be played with in a more hands on sense as opposed to on more abstract equipment measurements.
This site's an effective hider of text because it is entirely unfriendly to those losers who don't "consume their internet experience" through a tablet. Being such a loser, trying to read their stories is an aggravating waste of time.
So, can we please stuff it with the medium.com links?
And so, at the beginning of spring 2014, the pervcam 1.0 app for the nokia 1020 was released.
More Nokia smartphones has ever been sold in one week.
The paper does explain these limitations and it would be wrong to assume that this means we can see/photograph through fog, skin, clouds... But a semiconductor laser can have a spacial coherence long enough to do holography so if they said the source was a laser and non-conherent narroband, I'll give them the benefit of the doubt and assume they did something to destroy the laser coherence. Spinning frosted glass beam interrupters and other techniques are often used to despeckle laser light where it interferes with the laser's intended use.
Speckle does occur with non laser light sources but it isn't usually as strong because of the shorter coherence length. Go outside on a sunny day and look at your fingernails or a piece of black anodized metal, you may see the effect of white light speckle interference. The really amazing part of this technique is that they did it with such a low-res camera. While 42 Megapixels seems like ridiculous overkill for a phone camera, it doesn't hold a candle to the typical spacial resolutions approaching 400 Gigapixels for holography film. Extend and expand the technique into higher resolutions, illuminate with coherent laser light sources and it will be a valuable technique for laser imaging as well as other things. What else has point light sources against a dark sky and obscuring translucent material? The starry night sky. I knew the day would come when finally astronomers can have their cloud filter!
A chick breast is a flight muscle. Not even vaguely similar to mammary glands.
Besides which, why would you want to see what's behind one?
I photo bombed you from behind that wall.
Did they test frosted piss?