Dedicated LSI for a Microprocessor-Controlled Hand-Carried OCR System

The binary picture processing and recognizing stages of an optical character recognition (OCR) system have been designed using both flexibility of available microprocessors and speed of peripheral custom-designed integrated circuits. A dedicated large-scale integrated (LSI) processor performs edge detection and thinning of a 32 × 24 digitized one-piece pattern. The output signal–a set of 3 bit vectors describing the skeletonized character contour–feeds a microprocessor which controls the character recognition algorithm including pattern segmentation, filtering, feature extraction, and classification decision. This low-cost equipment is especiaUy suitable for hand-carried OCR systems where well-formed printed alphanumerics are to be read. However, continously deformed patterns like carefully handprinted characters are recognized as well. A system reading speed of 100 characters/s (or 30 cm/s) can be achieved.