modified:   HandGestureRecognitionSystem.sdf
	modified:   HandGestureRecognitionSystem.sln.docstates.suo
	modified:   HandGestureRecognitionSystem.suo
	modified:   HandGestureRecognitionSystem/HandGestureRecognitionSystemDlg.cpp
	modified:   HandGestureRecognitionSystem/HandGestureRecognitionSystemDlg.h
	add vector length threshold