A vision system for video head inspection

Ho and Tw are the geometrical measures of a video head for paring. A vision system was developed which inspects a video head for detecting automatically any defects which are visually noticeable as well as for measuring Ho and Tw values. Efficient image processing hardware has been developed using two transputers which run in parallel. Several new techniques are introduced, such as an algorithm for autofocusing within a second, a dynamic autothresholding technique which produces as many threshold values as wanted, and several defect detection algorithms for video heads. Experimental results showed that the system is very reliable. For a single video head, the system can perform all the measuring and inspection tasks in 3.2 seconds