I have been attempting to do exactly the same thing with a setup I am working on, and have a lot of "jitter" in the centroid. I believe that is is due to noise from the reflective surface of the image of the laser dot.
I am working with a b/w high speed camera, and have a zoom lens with an aperture adjustment.
Did you ever experience this, and were you ever able to come to a resolution?
I am working on face detection.This code is great, but I'm too curious about what is happening in facefind.dll. please send me your facefind.dll contents do I need this code . firstname.lastname@example.org