Slashdot Mirror
A Single Pixel Camera
BuzzSkyline writes "Scientists at Rice University have developed a one pixel camera. Instead of recording an image point by point, it records the brightness of the light reflected from an array of movable micromirrors. Each configuration of the mirrors encodes some information about the scene, which the pixel collects as a single number. The camera produces a picture by psuedorandomly switching the mirrors and measuring the result several thousand times. Unlike megapixel cameras that record millions of pieces of data and then compress the information to keep file sizes down, the single pixel camera compresses the data first and records only the compact information. The experimental version is slow and the image quality is rough, but the technique may lead to single-pixel cameras that use detectors that can collect images outside the visible range, multi-pixel cameras that get by with much smaller imaging arrays, or possibly even megapixel cameras that provide gigapixel resolution. The researchers described their research on October 11 at the Optical Society of America's Frontiers in Optics meeting in Rochester, NY."
It'll make current cameras, with simpler technology (less micromirror arrays and whatnot) cheaper? How? This stuff sounds expensiver.
This could have some awesome applications, especially on space missions. Imagine the next generation of mars probes and the resolution of the pictures taken if a camera near the size of current ones could have thousands of times the resolution. And of course, you also need to think about spy satellites. But perhaps the coolest application would be on space telescopes...
Early space cameras were single pixel and scanned their surroundings by their rotation.
Early fax machines worked the same way, but spun the paper around while the single photocell moved linearly left to right.
Hmmfff - Guess I'm giving my age away...
Excuse me, but please get off my Pennisetum Clandestinum, eh!
I have often thought that it would be really neat if you could get a visual image of radio waves like around for example 2.4ghz and be able to see exactly how your surroundings block/absorb/reflect those wave - in addition to seeing sources of the waves. They mention that might be possible by throwing a different sort of detector instead of a ccd in there? anyone know - would that be possible? do 2.4ghz waves bounce off anything else like light does mirrors, without getting scattered?
"Alcohol, cause of, and solution to, all of life's problems" -Homer Simpson
I think you may be missing the point (har har).
:-)
What they are recording is not solely a pixel, I would suspect, but the configuration of mirrors that achieved that point. So, there is a significant amount of information that they can extrapolate from just a random number seed and the final color. The plenoptic function that describes the transfer of light from the environment to the plane of the sensor is 4D. By capturing from many different non-parallel input rays onto a sensor, you can extrapolate a lot about the environment that isn't present in a purely parallel data set.
What I suspect they're goal is, is ultimately getting an array of mirrors onto a consumer-grade camera, and having it take three or four shots in rapid succession, then merge the information gained from each so that the result is more like having a High Dynamic Range image (well beyond the capabilities of any consumer-grade sensor) and use a tone-mapping algorithm to bring it back into a typical 8-bit range per component. It's complicated, but not impossible. Similar such things that are only a year or two old in the graphics community (flash + non-flash images being merged to give good color in low-light situations, multiple exposure images merged for HDR, etc) should come out in a couple of years as automatic modes for color correction, probably even on low-end cameras.
Of course, I still have a 6 year old point and shoot, so what do I know?
Any connection between your reality and mine is purely coincidental.
If you are interested you can find out a lot about the really fascinating and cutting edge science of computationally assisted optics, or whatever is the correct term. It is the same field as the people who have been experimenting with giant arrays of cheap cameras, capturing entire light fields that can be sliced in time and space and reprojected later on, etc. It is computers plus physics and a big dose of creativity, which is why it is related to SIGGRAPH too.
Anyway this is interesting and is based on different principles from current megapixel cameras, which is why they think it might improve current cameras too. Just like the way the spaghetti physicists were laughed at by Harvard's igNobel, even though they finally solved something Feynman couldn't crack and have discovered a new method for focusing energy.
Just off-hand, the one pixel camera and compressive imaging theory they have looks very interesting:
I'm not sure I agree with you.
The problem with CCDs is you need to clock the values off the capacitors. Either you use a machanical shutter to stop smearing while you do this, or clock it into masked areas, which means you either need to accept a 50% loss of area, or have micro-lenses, etc.
With the single pixel idea you shouldn't have too many problems if you can clock the system fast enough.
It also may be possible to create an array of mirrors with better behavioural uniformity than an array of detectors.
Diffraction may be less of a problem than initially thought as you don't neccesarily have to use mirror pixels singularly. For instance, if you can use blocks of 2x2 mirrors as the smallest 'feature', but they do not have to be starting with an 'even' or 'odd' pixel.
JPEG is designed for human vision and not optimal for other applications. Therefore it is possible that compressing the data in this way may be far more applicable to uses other than holiday snaps.