I solve foot jitter by increasing CJR for the legs when the character is standing in place, and then reducing it a little when the character is walking. In general, it should be higher for the legs when standing or walking.
If you're using a single Kinect, the feet may drift backwards when crouching or squatting. This is because the volume has no 'backside' and collision with the ground may force it backwards through the opening. This kind of error should be easy enough to fix in the animation program you export to.
With 2 Kinects, feet stability is better but the same error can occur when using the 90 degree setup. When using four to six PS3 Eye cameras, there is less chance of feet jittering away because there is more coverage. That said, I get reasonably stable results even when using 2 Kinect at 90 degrees.
If I still have trouble, I’lI turn to the pinning tools in Motion Builder to lock feet in place.
Here’s an example:
http://www.youtube.com/watch?v=jASC8IOsIqYIf you watch the video in stage 1, you can see the feet drift backwards when ‘Sister’ jumps forward. I tried to stabilize this as best as I could in iPi Mocap Studio but in the end I had to pin and release the feet in Motion Builder at the beginning of each jump. For the rest of the motion data, high CJR for standing still and medium CJR for walking was quite adequate.
If you’re expecting the feet to be perfectly locked and stable all the time, it's very likely that you will need to edit with another application that has pinning. (Like MB.) My hope is that iPi Mocap Studio will get this feature in the future.
G.