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."

Comments

101

[Timesprout]

This is me with Natalie Portman at a Star Wars convention (I'm the second 1).

Re:101

[Anonymous Coward]

Sorry but due to the lossey process it is impossible to tell if hot grits were present,
Please take another photo and maybe the randomness of the process will enlighten us.

Re:101

[Anonymous Coward]

The '0' was a hot grit you blind fool!!

Re:101

[TempeTerra]

Nice try, doofus, but that's clearly photoshopped.

that's one big pixel

[macadamia_harold]

Scientists at Rice University have developed a one pixel camera.

The camera's one pixel, but when you print it out full size, you get a mega pixel.

Re:I don't get it...

[Anonymous Coward]

Sure it's expensiverest at the moment. But with economisationalisation from upscalifying the process you could see it cheapifying quickly.

photo album

[chowdy]

. here's me at the grand canyon . oh man, here's where i got drunk off of my ass . here's me apologizing for this terrible joke

Had to be said...

[tonigonenstein]

One pixel should be enough for anybody.

Voyager worked (still works?) like that

[flyingfsck]

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...

Nothing for nothing

[syousef]

If you record only (lossy) compressed data, that will limit your image quality.
If you record things "pseudo-randomly", it'll be harder to get a predictable result
If you record a billion pixels instead of a million, you'll need to store them.
If you reduce the number of pixels, you reduce your redundancy.

It's still an interesting idea and probably has some specialist applications that will be very practical. But don't look for this in your Nikon or Canon camera in the next 10 years. Not sure what they are but if it can be made small enough I imagine a gigapixel camera on a space probe or better yet a space telescope (which can have more time to collect data) might be one. Of course it could also end up useless. That doesn't mean the technology shouldn't be explored. You never know what's going to provide the next breakthrough in understanding or application.

Re:Nothing for nothing

[The Panther!]

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? :-)

Other wavelengths

[vespazzari]

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?

can't wait

[zoefff]

can't wait for the first four pixel camera. Imagine the resolution of that one! ;-P

Re:There's the question...

[andy_t_roo]

within a certain wavelength range (down to where actual atomic structures break up the smoothness), a perfectly flat material with no resistance has perfect reflection (that's why the silver back on a glass mirror is so reflective, is very flat and conductive

Already done better in 1999

[goombah99]

Check this out In 1999 scientists at Los alamos national lab did essentially the same thing. Except they went one better---they also added in Phase detection by heterodyning the receiver.

Instead of using micro mirrors, the Los alamos team used an LCD which were more mature at the time. And Instead of using random modulation they used a progression of zenike polynomials and thus achieved much more control over the data compression.

patented too

[Anonymous Coward]

A patent for "A single element detector acts as an array"

Re:There's the question...

[Anonymous Coward]

Is it really cheaper to manufacture micromirror arrays that CCD or CMOS sensors?

Not likely. And it certainly doesn't sound mechanically robust to have moving parts replace a purely electronic chip. Cameras need to be rugged.

Also, what degree of photon loss do you have from the arrays? No mirror is perfect...

Imperfection in the reflectivity is probably secondary to diffraction, which will be a big problem for these small mirrors - and they would have to shrink even further for reasonable (multi-Mpixel) image resolutions. Diffraction is the biggest limiting factor for contrast in DMD projectors.

There are other problems with this design. First off, it is a time-sequential acquisition. The reconstruction algorithm assumes that all measurements are taken from the exact same scene. God knows what garbage it produces if you have moving objects or camera shake.

I guess their biggest motivation is to do the image sensing directly in compression space. Unfortunately, their compression space is vastly inferior to the compression space of, say JPEG. You see, JPEG is very cleverly designed in that it doesn't actually zero out certain frequencies directly - it just quantizes higher frequencies more agressively than lower ones, and that results in data that compresses better with a lossless compression algorithm (Huffman). By contrast, this compressive camera thing essentially directly zeroes out certain frequencies that have low amplitude. Not a very good idea perceptually.

it's probably been said..

[catwh0re]

...but it'd suck to have a dead pixel.

Practical uses. Why the stupid comments?

[mattr]

Pretty surprised at all the dumb comments on this story. The scientists involved are not demeaned by consumers being used to cheap megapixel cameras, nor by a secret lab having done something that sounds similar, nor by some patent existing. Slashdot really sucks!

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:

• A one-chip computer with transmitter, battery and 1 pixel camera could be worn on your cuffs or collar and capture/assemble from random angles through which it is jangled your entire surroundings.
  
• Could be used if mounted on a wire tip and wire oscillated giving many views of an object for cheap 3d scanning
  
• Camera could include one pixel per range of spectrum, recording a full electromangetic spectrum
  
• They are doing only some simple compression right now. If your current camera could do wavelet compression within the ccd you could certainly get much better pictures and reduce the storage needed.
  
• If current cameras can do all the work needed in 1/500 of a second that means they could be doing a lot more if only compression, transmission and storage are solved, that is what they are working on.
  
• The one pixel camera uses random projections to achieve a certain density of information that seems to be constant throughout the light field they are capturing. This means if they store orientation and time accurately, their data can be sliced at constant quality in any direction, so it is homogenous data which is good. Imagine slicing diagonally through Kraft cheese block or through swiss cheese.
  
• Compressive imaging might help video camera manufacturers wrap their heads around recording at far higher frame rates, including side radio bands for orientation, or combining multiple image sources. Compression in the imaging chip means less data to handle elsewhere.
  
• If you read some of the bibliography (the Architecture one) you will see use of Haar wavelets to reconstruct an image from a 3-dimensional (200,000 voxel) data structure which performs much better than a 2-d one due to the sparseness of data. This paper also talks about the use of bands for which CCD use is impossible.