Pipelined algorithm-specific hardware for shape comparison of tableglass

Abstract

An instrument has been designed to enable a glass-blower to check the shape of a glass in real-time. The outline of the glass being inspected is displayed on a television monitor superimposed on the outline of'a reference glass so that differences in shape between the two can be ascertained. This instrument uses techniques of optical inspection and implements an algorithm which was first developed on a conventional image processing system and then translated to a hardware implementation to provide the inspection facility. A novel pipelined architecture is used to implement the algorithm to enable operation at video rate at low cost; this avoids the use of a high-speed (and expensive) computer system. It also provides a precise measure which is obtained instantaneotisly, without contact. At the 'hot end' of manufacture, this facilitates rejection of faulty items prior to cooling. At the 'cold end', this is a major step towards automation of inspection and sorting of glassware. Checking of shape is naturally not restricted to the glassware industry; this instrument may be useful in other areas of manufacturing.