High-Speed Video Using a Dense Camera Array

karvind writes "Researchers at Stanford have demonstrated multi-thousand frame-per-second (fps) video using a dense array of cheap 30fps CMOS image sensors. A benefit of using a camera array to capture high speed video is that we can scale to higher speeds by simply adding more cameras. Even at extremely high frame rates, our array architecture supports continuous streaming to disk from all of the cameras. Now we know where to use 100TB tape drives and what to expect in the next sci-fi movie."

Comments

Re:Questions

[conteXXt]

time pulse code. (SMTPE? or something like that)

Same way they sync audio and video in sound studios.

Video track (or a seperate track) carry a pulse carrier. Audio track syncs to that.

Re:What's the big deal?

[moriya]

I believe the point in producing this is to show that instead of purchasing expensive high-framerate cameras that has some sky-high pricetag, one can use an alternate and cheaper solution by using CMOS sensors. So let's try placing a couple of things into perspective.

Say you require a camera that can record say 90fps. To a manufacturer of electronic parts, this can be achieved with a little bit of engineering. Basically, take 3 of those 30fps CMOS sensors, pack them together, set a uniform color correction setting, and an interface to send the captured information to. All this would probably costs lots less than a specialized camera that can capture 100fps or so.

If you were to walk around in a computer shop or your local Best Buy, CompUSA, Microcenter, Circuit City, or Fry's, you might have noticed that there are quite a few webcams around, all of which uses the same 30fps CMOS described at the link. The CMOS themselves are likely cheap enough that, in theory, you can assemble a few together and have a 90fps camera. I would assume that the spatial distortion would be next to nil since 3 sensors are closely together.

Please correct me on any points. I believe the concept is interesting and would have some useful uses out there (ie. spectator sports, research, film).

Re:shutter speed

[Kiryat Malachi]

All of the CCDs run at 30 FPS. So, yes, they can scale this almost endlessly (until the parallax variation from non-colocated image captures becomes extreme, basically, or until the trigger timing required becomes too hard to achieve and jitter begins to be large enough to significantly alter your frame timing/sequencing).

The trick is that A runs on 0.000, 1.000, 2.000, etc. while B runs on 0.001, 1.001, 2.001, etc., C is on 0.002, 1.002, 2.002, etc. (units are frames relative to a starting time), and then the frames are sequenced appropriately (ABCABCABC etc.). This gives a very high frame rate while using relatively low-cost sensors - effectively, they're exploiting parallelism as a way to increase the array's effective sampling rate.

Basically, if you have N sensors capable of sampling X times per second each, and are capable of accurately triggering each sensor to a high degree of time accuracy, your effective sampling rate can be NX. Neat trick.