v.motion v.motion implements "frame differencing". v.motion implements "frame differencing". The current frame is subtracted from the previous frame. the differences are generally caused by movement in the image. This is a key component in classic softVNS motion tracking.	from the library : softVNS Format : External Environment : jitter / max commercial Max 4.x http://homepage.mac.com/davidrokeby/softVNS.html