There are two or four video heads in most of VCRs. Video heads used in one VCR should have similar geometrical and magneto-electrical characteristics. Ho and Tw are the geometrical measures of a video head for pairing. This paper is aimed to develop a vision system which can examine a video head not only to measure Ho and Tw values but also to detect defects, if any. A cheap and fast 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 show that our system is very reliable. For a single video head, our system can perform all the measuring and inspection tasks in 3.2 seconds.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.