Signal Processing Techniques In Commercially Available High-Speed Optical Character Reading Equipment
John Hicks, J. C. Eby, Jr. · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1979
To be competitive in todays data entry marketplace an OCR machine may be capable of reading data at rates up to 6000 characters/second. This may require the signal processing to be performed at rates approaching 107 pixels/second - implying an equivalent number of arithmetic operations of an order of magnitude above this rate. These rates preclude the use of conventional array processing units and create special problems for equipment manufacturers. This paper describes the techniques of real time image enhancement, array and lens compensation, automatic shading correction and two dimensional digital filtering and thresholding incorporated in a high speed OCR reader.