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Researchers Developing Single-Pixel Camera

Posted by Zonk on Thu Jan 18, 2007 04:43 PM
from the needs-a-very-small-monitor-to-view dept.
Assassin bug writes "According to the BBC, researchers in the US are developing a single-pixel camera to capture high-quality images without the 'expense' of traditional digital photography. The idea behind such a device is that traditional digital photography is wasteful. Most of the information taken in by the camera is thrown away in the compression process. From the article: 'The digital micromirror device, as it is known, consists of a million or more tiny mirrors each the size of a bacterium. "From that mirror array, we then focus the light through a second lens on to one single photo-detector - a single pixel." As the light passes through the device, the millions of tiny mirrors are turned on and off at random in rapid succession. Complex mathematics then interprets the signals assembling a high resolution image from the thousands of sequential single-pixel snapshots. '"
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  • Yes, it's a dupe. (Score:5, Insightful)

    by Anonymous Coward on Thursday January 18 2007, @04:44PM (#17671236)
    A Single Pixel Camera [slashdot.org]
    Posted by CowboyNeal on 10-20-06 12:44 AM
    from the high-tech-pointilism dept.

    From the FAQ:

    Sometimes I see duplicate stories on Slashdot. What's up with that?

    These are just mistakes on the part of the staff. They happen. We have posted over ten thousand stories in our history. The occasional duplicate is inevitable.

    If you see a duplicate, you can mail the story's author. If the story is still quiet, we may pull it down. However, once the comments are rolling in, we often leave the story up so that the discussion can continue.

    Some people have suggested that there might be a software solution to this problem. If you think you've got one, visit the Slashcode site and submit a diff. As long as it isn't a performance hit, I'd consider using it. (Be aware however that the trick of searching for duplicate URLs isn't as helpful as you might think, since the same story can appear in multiple locations.)


    So if you really want to complain about it, consider contributing a Slashcode [slashcode.com] patch to fix it.
  • If the one-pixel camera behaves like a traditional digital camera, I will need to take 100 pixels to get 20 decent pixels that I can use.
  • In related news, a major roofing manufacturer has announced the "single shingle" roof. It consists of a small plate that is quickly moved about above a building during a rainstorm to block each individual raindrop. This eliminates the "complexity" of asphalt shingles.
    • by Chandon Seldon (43083) on Thursday January 18 2007, @05:10PM (#17671804) Homepage

      That would work... if shingles were really expensive and the mechanism to move the one shingle around at the necessary speed were comparatively cheap. Oh... and you knew that you never needed to block raindrops in two places at the same time.

      There are tons of ideas that work great in computerized systems that sound *really stupid* when you think of doing something that seems similar but uses other materials / technology. I mean - consider the mechanism of an ink jet printer from the perspective of a portrait artist who works with pencils...

  • by Anonymous Coward on Thursday January 18 2007, @04:47PM (#17671308)
    Bet it'd suck to have a bad pixel with that camera, huh? :-)
  • Finally! (Score:2, Funny)

    by Anonymous Coward
    Now we can get pr0n at the level of quality in Duke Nukem! One fleshy-pink-colored pixel is enough to get most me off...
  • 1MP? (Score:5, Funny)

    by UPZ (947916) on Thursday January 18 2007, @04:47PM (#17671312)
    Next thing you know, they'll be inventing a single core processor.
  • RAW format anyone? (Score:5, Interesting)

    by Anonymous Coward on Thursday January 18 2007, @04:48PM (#17671326)
    > Most of the information taken in by the camera is thrown away in the compression process.

    Doesn't the RAW format take care of this?
    • by John Meacham (1112) on Thursday January 18 2007, @05:19PM (#17671996) Homepage
      The problem is not getting at that extra information, like you say, we can already do that with RAW. the problem is that a lot of resources (such as CCD area) go into capturing this extra information which is then simply discarded. By taking a random sampling of pixels, one gets exactly as much information is needed to construct the compressed version of the image without waste. plus, with only a single CCD, you can make it incredibly sensitive, to the point where it can count single photons. Heck, you could probably have some fun with wavelengths. different wavelengths get diffracted slightly differently, if you could take advantage of that to redirect photons of different wavelengths at the sensor. you could have a camera that takes _full spectrum_ pictures. not just at the single pretty but not very informative red green and blue lines. (tetrachromats rejoice!). Full spectrum sampling in a small package would be really cool, I mean, that is tricorder technology. This is very neat research.
      • by Pieroxy (222434) on Thursday January 18 2007, @05:34PM (#17672290) Homepage
        There is always a catch, however. Let's take an example of a 1MP camera, taking a picture at 1/100th of a second. Each CCD can acquire light for a full 1/100th of a second. But each one is small and as such, not very sensitive.

        Let's say this new 1 pixel camera is set-up to take a picture of 1MP at 1/100th of a second. Each one of the 1M mirrors will reflect its light on the CCD for ... (1/100)/1000000 th of a second, because only one pixel (of the final image) can be recorded at a time. So yes, the new sensor will be more sensitive. And it better be ! 1 000 000 times to be correct (for 1MP pictures.)

  • complex mathematics? (Score:4, Informative)

    by superwiz (655733) on Thursday January 18 2007, @04:48PM (#17671338) Journal
    Surely, you mean "complicated". Mathematics already has a use for the word "complex".
  • Well, there's no reason a digital camera *has* to throw away any data at all. It's likely the case that all digital cameras do perform on-the-fly JPEG compression, but it's not a limitation of the hardware, so why bother reinventing the wheel if you really care about losing data that much? Just make a digital camera that saves pictures as some lossless format.

    And at any rate, how are the single-pixel cameras throwing away any *less* data than their plain digicam counterparts? Doesn't it all just depend on t
    • I think this design is sort of like an ultra-fast scanning back [wikipedia.org]. A scanning back is a high-end type of digital camera sensor where the sensor has only a very small resolution, but it physically moves and takes a frame at each step. The many resulting frames are then interpolated together appropriately. This can produce EXTREMELY high-resolution images (we're talking 100s of megapixels) but it is sloooow (minutes or hours per exposure). Good for art reproductions and such.

      As I understand it, this camera
  • FTA: Compressive Sensing is an emerging field based on the revelation that a small group of non-adaptive linear projections of a compressible signal contains enough information for reconstruction and processing. We have developed algorithms and hardware to support a new theory of Compressive Imaging. Our approach is based on a new digital image/video camera that directly acquires random projections of the signal without first collecting the pixels/voxels. Our camera architecture employs a digital micromirro
  • by MuChild (656741) on Thursday January 18 2007, @04:49PM (#17671364)
    1) Create a million bacteria-sized mirrors. 2) ???? 3) Profit!
  • by heroine (1220) on Thursday January 18 2007, @04:50PM (#17671390) Homepage
    Always thought the single pixel idea would be more practical in a reflector telescope. Such a telescope could have a much higher dynamic range than any other telescope due to the extra money available for the pixel. The telescope would use the Earth's rotation to scan one axis and servos to scan the other axis.
  • by jo7hs2 (884069) on Thursday January 18 2007, @04:50PM (#17671394) Homepage
    Oh great, now I'll end up with a camera with a stuck or hot pixel and be totally screwed. Thanks, progress.
      • Re: (Score:3, Insightful)

        Actually, I don't think you could. If you had a mirror that got stuck into the 'on' position (i.e. it's pointing at the single sensor), it would partially blind the sensor whenever any other mirror was also pointing at the sensor. If that one mirror happened to be seeing pink, the entire photo would have a pinkish hue. If it happened to be seeing white, the picture would be washed out. If it happened to be seeing pitch black, well, then you're in business.
  • by toby (759) * on Thursday January 18 2007, @04:51PM (#17671416) Homepage Journal
    And this story hit the UK Guardian on 9 Nov 2006. [guardian.co.uk] (via CS maven my slice of pizza [blogspot.com].)
  • by Timesprout (579035) on Thursday January 18 2007, @04:52PM (#17671422)
    This is me skydiving
    .

    This is me swimming with dolphins
    .

    This is me at the grand canyon
    .

  • ...with only a single CCD pixel, they can spend all their resources making it exquisitely sensitive, so as to outperform normal array CCDs.

    Of course, they'd have to do that anyway, because to get a decent shutter speed they're already going to have to 'scan' the viewed area extremely quickly. It's the old tradeoff of serial versus parallel processing.

  • by ScentCone (795499) on Thursday January 18 2007, @04:52PM (#17671434)
    Is it just me, or does the concept seem inherently more complex and fragile than a multi-pixel sensor with light cast on it?

    And how can this possibly deal with the equivalent of a range of shutter speeds in front of a standard sensor? Perhaps it's a matter of how many times the pixel is exposed to the same part of the lens' projection in repeated scans... but that just seems clunky, and that much harder/slower to re-assemble into a stored image.

    And it doesn't stop the megapixel chest thumping - it just starts up megamirror arguments, instead.
    • by Jeff DeMaagd (2015) on Thursday January 18 2007, @05:01PM (#17671632) Homepage Journal
      Micromirrors are actually very reliable and even exceed the lifetime of a typical LED now, of hundreds of thousands of hours of constant flexing. It turns out that nano-scale objects have different properties. A piece of metal on the nanoscale is likely to be a single crystal and that usually eliminates the fatigue issue. I think this has more uses in the sciences though.
  • by JohnnyGTO (102952) on Thursday January 18 2007, @04:52PM (#17671440) Homepage
    oops, crash sevem million years bad luck !?!
  • Look how many MegaMirrors my new camera has!
  • Excuse me (Score:3, Interesting)

    by markov_chain (202465) on Thursday January 18 2007, @04:53PM (#17671460) Homepage
    Please don't move until I sequentially activate a few hundred thousand micromirrors!

    'nuff said.
  • Dupe (Score:2, Informative)

    From the mysterious past: http://science.slashdot.org/science/06/10/19/22552 39.shtml [slashdot.org].
  • It sounds very much like Sigma-Delta Modulation (http://en.wikipedia.org/wiki/Sigma-delta_modulati on [wikipedia.org]). Lots of samples in time, fewer bits.
  • by Xoltri (1052470) on Thursday January 18 2007, @04:55PM (#17671502)
    The article says that this new camera will have do do "Complex mathematics to interpret the signals" but at the same time will "do away with the need to process and compress each image". So which is it? I just don't see how this will save anything if you have 1 pixel doing something 5 million times or 5 million pixels doing something one time.
  • by sharkb8 (723587) on Thursday January 18 2007, @04:58PM (#17671574)
    You can have a million little moving parts in your camera!

    The microelectrical mechanical device fabrication techniques used to make the DLP scanning mirrors are taken from tech used to etch transistors. Instead of a circuit bring etched, a movable mirror os etched into slicon or other substrates. And you end up with a bunch of little tiny mirrors moving around on a portable device. Moving parts tend to wear out more rapidly than solid state parts, and are more easily broken. I'd be interested to see how durable this tech is. DLP doesn't have this issue because no one carried a DLP projector or TV around.
  • by Solandri (704621) on Thursday January 18 2007, @04:59PM (#17671604)
    Low light sensitivity. Digital cameras gain light sensitivity by acting as light buckets. Moreso for CMOS sensors than CCD, but the important thing is that all those sensor pixels are collecting light for their individual pixel simultaneously - in parallel. With a single pixel sensor, this light collection would have to happen in series to achieve the same light sensitivity. If your shutter speed in low light is 1/25 sec with a 5MP traditional digital camera, in order for a single-pixel camera to take the same picture it would need an exposure time of (1/25 sec/pixel)*(5M pixels)*(10% assumed algorithmic efficiency) = 20,000 sec = 5 hours 33 min 20 sec.

    Of course since you're doing all this with mirrors, you could set up a megapixel array and have different mirrors shine at different pixels simultaneously (just like a DLP). But that seems to defeat the purpose of the whole rig.

  • The basis (Score:3, Informative)

    by Jerf (17166) on Thursday January 18 2007, @05:19PM (#17671986) Journal
    Here's some of the basic math behind the idea:

    When you lossfully compress an image, you are literally throwing away data. If you compress a 1MB image down to 100 KB, which with JPG is still very good quality, you are mapping many, many, many slightly different but ultimately very similar source images all onto the same compressed image.

    Consumer cameras "waste" time starting from a full lossless image, and compressing it with JPG; the waste comes from collecting all of this data that has no bearing on the final result. (Anything that stores the .RAW of the image isn't doing this compression, it's storing the entire data set.)

    The idea of this system is that by mixing the pixels together in a certain way, we can collect less information in the first place. For what would be a 1MB picture in a standard camera, you'd start off by only collecting 100KB of information, and then computing the image from your sequential numbers.

    Two problems leap to mind:
    • I find it very, very hard to believe that "random" is the optimal approach. I would have thought there would be something much better than that for the bases, but I could be wrong. (There almost certainly is something better than "random" but it may not be better enough to justify the computational expense.)
    • JPG bases were carefully designed to match the human visual perception system and make it difficult for us to perceive the compression artifacts. The compression bases in this situation will have to be optimized for information gathering, which won't be the same as the human eye, which will result in somewhat inferior pictures, bit for bit. If you know what you're looking for, you can see it in their sample pictures; it's going to take a lot more bits to make that mosaic effect "go away" that it will to make JPG artifacts "go away".
    A clever PhD may be able to solve both problems in one swipe, by using a clever mirror progression that happens to map better to the JPG standard. (You can't get it perfect though because you can't predict in advance how many bits go to one JPG block, that's computed dynamically.)

    It works, and it's a clever algorithm, but I would definitely still question its practical usefulness over a conventional imaging system. I think the current trend of compression is temporary; the megapixel race should start to slow down (who needs 100megapixel pictures of their baby?) and then as cameras and storage continue to advance, we'll start getting uncompressed or losslessly compressed images instead. I could see this technology winning the race to be the first to produce a single camera that matches the image capturing power of the human eye, though; by manipulating the incoming light you may better be able to manage widely varying light levels.

    (Finally, bear in mind before posting criticisms of how impossible this all is that they appear to have actually built a device that does this, which trumps skepticism.)
  • by meanfriend (704312) on Thursday January 18 2007, @06:37PM (#17673332)
    Single pixel images will revolutionize the efficiency of porn sharing.

    Are you into hentai? Here you go! .....................

    Barely legal teens? Coming right up .......................

    Even goatse freaks dont need to be left out:
    .

    Though I'll probably get modded down for that last one :(
  • by BenJeremy (181303) on Thursday January 18 2007, @08:44PM (#17675020)
    Just my luck, and the warranty says I can't return it unless I find at least 4 dead pixels!!!
    • Yep- and just as crappy as the original DLPs. DLPs work because they have *very* high processing rates- unless the subject of the picture you're taking is perfectly still, I don't see this as being a big advance in digital photography.
                • How many bits at a time do you think a harddrive head can read?

                  One per head, buffered. But unlike bits on a hard drive, subjects in real life MOVE. Just because you read a pixel on one side of the picture one nanosecond, doesn't mean that the next nanosecond that pixel will be the same. By using the mirrors instead of a massively parallel system, you're moving the serial from the connection to the hard drive or long-term memory storage, to actually taking the photo. Which will, at best, cause some pre
                  • Re: (Score:3, Informative)

                    "Look at the website referenced in the story- you'll see what I mean in their sample photos of even still items"

                    *pmsl* what way exactly do you think that photos of a STILL SCENE in any way reflect (hehe, reflect) image loss that WOULD be caused by taking photos of a moving scene?!!

                    Anyway, this isn't a simple case of turn-by-turn turning on each mirror then off again, at any one sample time multiple mirrors will be reflecting to the sensor, and for each photograph taken, each mirror will have been read from