1) Kinect uses a contributed library and specific hardware. So such question doesn't belong to the generic Programming Questions but to either of the two other specialized forum (otherwise, nearly all questions are programming questions!).
Since it is more software oriented, I will put it in the former section.
2) To my (very small) knowledge, there are several Kinect libraries already. If you don't specify which one you use, you risk not to have an answer. (Unless somebody knows well the issue you mention.)

sorry for putting in the wrong section. I am using the openkinect library by the danial shiffman and trying to get the larger video display size than the 640*480 size. Can it be possible using SimpleOpenNI library as i am using mac so cant use windows libraries. thank you

Hi Suhitp,

Thanks guys for the quick response.

Hey Suhitp,

No I am using depth camera so as to track the user movement in front of the camera. can it is possible with depth image also????