An Hough based recognition system for electronic schematics conversion to CAD format

The processes carried out in transforming scanned schematics to the textual files of a few CAD packages are discussed. After separation of text from graphics, mask convolution is implemented for noise reduction and thinning. Chain vectors are used to establish the possible occurrence of components while tracking. Parameters calculated from the chain vector method and integrated with an adaptive Hough transform (HT) scheme verify and identify the various components. An adaptation of the HT makes use of point prediction to identify disjointed collinear points-a fundamental flaw in the basic HT method