help with blob tracking in a mapped area, newbie

Hi,

i am working on an installation (school project) where i need to track motion in a certain area. the Kinect is required to be used for that. i started to work on blob tracking, though i need advice and help to continue. i need to track both presence in the whole area and need to divide it into two - an outer and an inner circle. in the inner circle i would like to see the numbers of people (as blobs) - also i wish to see if there is movement from the outer circle into the inner one. i have also problems to sort out the blobs, as it is only the people i track (kinect is above them).

as i am inexperienced with jitter, any help/hints would be appreciated.

thanks in advance
edit

my messy patch, sorry for that: