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Combining Two Kinects To Make Better 3D Video
suraj.sun sends this quote from Engadget about improving the Kinect 3D video recordings we discussed recently:
"[Oliver Kreylos is] blowing minds and demonstrating that two Kinects can be paired and their output meshed — one basically filling in the gaps of the other. He found that the two do create some interference, the dotted IR pattern of one causing some holes and blotches in the other, but when the two are combined they basically help each other out and the results are quite impressive."
How cost and/or physics prohibitive would it be to exploit the fact that "IR" actually covers a number of frequencies of invisible-to-the-naked-eye light with similar properties? Could one modify a Kinect with appropriate narrow-band filters, so that a second Kinect, with filters for a different narrow band wouldn't even see the dot pattern of the first? If possible, how many Kinects would it be possible for(or, at what point does the required narrowness and wavelength tolerance requirements become absurdly costly?)
Is that A)Wholly impractical, because of some sort of effect the reflecting materials would have on the IR wavelengths, B)Sure, it's possible; but have you checked the supplier's price list for narrowband IR filters recently, or C)Just a bit of ebay and some steady hands?
Perhaps more practically, I wonder if the Kinects could(with some mixture of hardware shutters and firmware or driver mods) be made to trade off sample rate for coverage(ie. if the kinects are ordinarily taking 60 frames/second, could two kinects be made to take 30 frames/second each, turning off their IR source when it isn't their turn, and turning it on when it is) or does their mechanism of operation require too much time to calibrate itself on startup?
What feat would that be that one stationary ear could do as well as kinect?
Recognize your voice from the kitchen
The "good ol' brain" does a fairly crappy job, actually. 3D vision systems like these tend to perform quite a bit better than we do. And we only do as well as we do because we can use a lot of indirect clues based on our long experience with a 3D-world - we know how big stuff normally is, for instance, so we can judge distance from size. Mess up those clues and we completely lose it.
And even with good clues we don't actually measure distance well. Have somebody place items on a parking lot or some place like that, then try to guess the distances. Not going to be very accurate. Try to estimate distance vertically rather than horizontally and you'll do even worse; you have fewer clues and less experience to fall back on.
Trust the Computer. The Computer is your friend.
... is good, but I'm holding out for 4 Girls, 3 Kinects, 2 Boxes, 1 Cup :)
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Unfortunately, this wouldn't work very well. Light tends to lose its polarization somewhat when it bounces off of things. In a theater that's OK because you can use a special screen that maintains the polarization. Band limiting each kinect would be more effective than polarization (and would also scale better - polarization only allows for 2 kinects; the bandpass idea would only be limited by how good your filters are).