Visual servo auto-focusing using recursive weighted least-squares for machine vision inspection

Auto-focusing of an electronic camera is an important task in automated machine vision applications. In this paper, we propose a visual servo auto-focusing mechanism using a moments based focus measure. A recursive weighted least-squares focusing algorithm is developed to drive a camera to the focused position. It is shown that the proposed autofocusing scheme can guide the camera to the focused position in a fast speed regardless of the initial position and the object to be focused.