A TOPOLOGY-BASED COMPONENT EXTRACTOR FOR UNDERSTANDING ELECTRONIC-CIRCUIT DIAGRAMS

An automatic understanding system using the techniques of image processing, pattern recognition, and artificial intelligence has been developed for electronic circuit diagrams. A heuristic piecewise linear approximation algorithm is proposed to approximate picture segments for primitive recognition. On the basis of topological context, a one-pass manner called the relational best search method applies a depth first search technique uniting a set of specified rules during the traversal of a circuit diagram. This method combines the constituents of each circuit symbol or character into a cluster. All the clusters together with the remaining components are extracted and grouped into the three categories as soon as the traversal is finished. A variety of electronic circuit diagrams have been used for testing the component extractor. So far, the present extractor has shown favorable results.