[opendtv] Re: More on the 1-pixel camera

  • From: "Albert Manfredi" <bert22306@xxxxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Sun, 22 Oct 2006 21:15:51 -0400

Tom Barry wrote:

I don't at all understand how this could work. It seems there would
be too little information. Whether they capture all those one pixel
samples randomly or in a normal raster scan they are claiming to
capture a megapixel image using only kilopixel samples. Assume for
the moment they did not use their new mathematics to process
those samples but instead stored them to disk. Thus, without any
additional compression (or motion comp) they would already be
storing a supposedly good (?) image with a many hundred to one
compression ratio. I'm skeptical.

Am I missing something obvious or are they stretching the "several
thousand times" quantity a bit.

No, I think there is a bit of hype there. The EE Times article did say "tens or hundreds of thousands of measurements, not millions." I think the megapixel comes from the fact that the sensor is a 1024 X 768 DMD. Not necessarily that the full image resolution must be transferred to a display. That's my take.

Not too different from standard MPEG techniques, where a megapixel image can be created from 100s of kilopixels worth of encoded data.

Also, you mentioned motion compensation, but I don't see that translating to this scheme. Motion compensation depends on redudancy in most of the image, while small parts change. But here, where each new sample is randomized, one would hope there's essentially no redundancy at all.

My impression is that this scheme is mostly aimed at reducing the image sensors, more than to achieve greater compression efficiency. In that regard, somewhat similar maybe to one-bit audio, which was also aimed more at alllowing for higher accuracy A/D and D/A conversions with simpler hardware than possible with multi-bit samples, not so much to achieve better compression.


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