Best depth camera for skeleton tracking

I’m about to buy a bunch of Kinects for a project that will do skeleton tracking from about four Kinects. I’ve used both OpenNI and the Microsoft SDK before and I’m leaning towards OpenNI because

  1. I want to run stuff on a Mac if possible.
  2. the Microsoft SDK requires a Windows Kinect which currently cost about 2-3 times more than the XBox Kinects.

However… it’s been a few years since the Kinect came out. There are new cameras about, like the Asus Xtion which is a bit more expensive than a second hand Xbox Kinect but is small, USB powered and compatbile with OpenNI 2.0, which the Kinect is not. The cost was almost enough to sway me but then I saw this video:

http://www.youtube.com/watch?v=jg-RXRpMmNY
OpenNI running on a Raspberry Pi using an Xtion. Given how painful it is to use multiple Kinects simultaneously, plugging them all into their own raspberry pi and sending data over ethernet sounds very tempting - if it works and is reliable.

So… I was wondering what other people’s experiences are of late. Are there other depth cameras that have been released within the past year that I should be looking at? (NB For me at least, stuff needs to be available to buy now) Has anyone had success running stuff on a raspberry pi? Has anyone used OpenNI 2.0? Is the advance from 1.5 enough to warrant new hardware?

Links to blogs I should be following that would have answered this question are also welcome!

I have been using these lately.

http://www.primesense.com/solutions/sensor/

I have found that I can never get any Xtion Pro’s. They Are never in stock/Do they even make them anymore?

Primsense have a far and close distance model. The soon to be released Capri sound very good to.

Is the skeleton tracking quality noticably different from the kinect at all?

i havent noticed any difference.

The kinect acually uses a primesence SoC. I believe the hardware is pretty much the same between the two devices.

best way to get Xtion Pro is to add a notification on NewEgg and order them the same day

xtion pros are currently in stock at newegg
http://www.newegg.com/Product/Product.aspx?Item=N82E16826785030

I also just pushed an early OF/OpenNI2 wrapper (just depth/RGB) for it here:
https://github.com/jvcleave/OpenNI2AppExample

I’ve been using the XTion Pro with OpenNI for skeleton tracking and the Kinect with the MS Kinect SDK and I’ll say that MS Kinect tracking is generally more robust and reliable. OpenNI gives ghosts, weird no-confidence results, and generally feels more noisy to me. I had to include a lot of work arounds for users entering and exiting the frame. The devices themselvs are however very easy to work with and you can plug them into a RPi as you’ve noticed. That alone makes it very attractive and streaming skeleton data over UDP is a great idea. Do be sure that you have something to ensure that you’re finding actual good skeletons and definitlely look into the new OpenNI2.0 and NiTE2.0, they’re far better designed APIs than the 1.x versions.