There needs to be better buzz blogger integration

The generic rss import gadget sort of works, but the rss headlines of buzz are really useless, only saying that there is a new buzz from username- they should have the first sentence at least of a buzz item:

Xbox Project Natal - Estimated Specs

This video went up yesterday, was pulled down and then restored later for some reason (not before other youtube users posted their own copies and gathered many more views than the official channel)



The video states 30Hz, and there is an interesting shot starting at two minutes.




From the above screenshots it's possible to count the number of pixels horizontally and vertically, and also most of the depth bins (there may be more range beyond the wall behind the person but a minimum count is better than nothing).

So there at least 18 depth bins, counted at 2:01-2:04 in the video. Each is maybe 2 or3 inches spaced.

The resolution looks like 64x64.

Structured Light For 3d Scanning

I learned a little about structured light from the 2008 House of Cards Radiohead video and more since Kyle McDonald created an open source google code implementation- but only very recently really gotten into how it works.

Simulated Structured Light

I had trouble getting good scans initially and I thought it would be good to create a perfectly controlled setup that didn't require a projector or camera- instead generate scenes from software, projecting textures onto 3d objects.

One of the generated input phase images:


Output from the google code ThreePhase processing app:



The obvious improvement is to add in an obj loader to this program, instead of just generating a semi-random blobby shape.

Real World Scans

I was hoping for a lot more but managed to get a few scans of people during a New Year's Eve party:

From 2009.12.31_nextyear

From 2009.12.31_nextyear

From 2009.12.31_nextyear

Those were all made using modified versions of Kyle McDonald's slDecode and slCapture programs. I'll post those somewhere eventually.


Matlab Script

This script is currently very very slow, but it's good to be able to debug in matlab and have easy access to fft and other functions.

Wrapped phase:


Unwrapped phase:


Note the vertical lines where phase propagates vertically in glitchy ways- some filtering (and even slower processing time) ought to be able to clean that during the flood fill.

Next

I hope to go mainly in the direction of high resolution high fidelity scans, as opposed to high frame-rate low sample-time scans, though I think I can access several high frame rate cameras for use in the latter. There is also lots of room for improvements (especially at the phase unwrapping stage) that would benefit either one of those.

Natal competitor: Optricam?

For a while I was worried that after Microsoft acquired 3DV Systems and their depth sensing ZCam, which might have been available at the beginning of this year, they were going to release the Natal exclusively for the Xbox and the possibilities for non-MS sanctioned applications would be severely hampered. And then to have to suffer delays for software I don't care about when the hardware may be ready now. But there may be similar products from other vendors due to arrive soon.

I learned about the PMDTec Camcube a few months ago. It is a lot less expensive than a Swissranger, but there are no U.S. distributors and nothing on the web from customers that are using it.

But this last week there was this press-release about a Belgian company Optrima (Israel, Germany, Switzerland, and now Belgium- all the U.S. flash lidar vendors seemed to have missed the boat on low cost continuous-wave IR led range finding systems to instead focus on extremely expensive aerospace and high end mobile robotics applications) teaming with TI and a body motion capture software vendor (Softkinetic) to produce Natal/Zcam-like results in the same application area- games and general computer UI. There is mention of Beagleboard support in the press-release, so having say Ubuntu be able to communicate is very likely.

Hopefully TI will really get behind it and all the economies of scale that MS can bring to bear can be matched, and it will only cost around $100.

Also, I'm seeing more and more red clothing and jumpsuits- possibly with specially IR reflective component, which makes me suspicious about the limitations of these sensors (also using them with windows letting in direct sunlight is probably out of the question).

Using a canon camera to view jpegs

I tried using my Canon camera as a picture viewer, putting some downloaded jpegs on it- the pictures didn't show up at all when I tried to review them, only the pictures I had taken with the camera. Renaming the pictures to have camera names like DSC_0025.jpg made the camera show a question mark icon for the picture at least.

A little searching later I discovered a tool called paint.net, which saves jpegs in the proper format so the Canon will like them. The other trick is to re-size the canvas the picture is on so all dimensions are multiples of 8.

paint.net itself is somewhat interesting, quicker to load than Gimp but not so much easier or more intuitive or like Deluxe Paint that I'll use it for anything else.