I just found this very useful Processing wrapper for OpenNI. It included a number of useful functionalities in OpenNI.
OpenNI in Processing – User Tracker
The second example from the Java binding of OpenNI, the User Tracker.
It crashes when I run it in the 64bit OSX environment. For the demo, I run it in a 32bit Windows 7 machine.
OpenNI and Processing
Based on the latest Java binding of the OpenNI, I put the SimpleViewer sample into a Processing sketch. The trick is to convert the BufferedImage into a PImage object for display.
I did testing with another sample – UserTracker. It seemed that it can only run in 32 bit environment, not the 64 bit.