Character presence processor

Abstract

A method and system for automatic optical character recognition wherein a continuous flow of image data is processed at a high scan rate. A two dimensional array of self scanning photo sensors is disposed to read characters located on a writing medium. Analog outputs of the cells of the photo sensor array are converted to a continuous flow of binary signals representing character segments or the absence thereof. Feature codes are generated in a ROM to produce a multi-bit feature code characterizing unique relationships between character segments. For each row and column scanned, a representative feature code is produced with a sequence of such codes representing a complete scan of the array. The features codes are received by a decision network as they are generated by the ROM. The decision network is provided with a multiplicity of nodes, each node being accessible to every other node by a one state change to produce a representative output character code. The multiple character codes which are produced during the movement of a single character across the sensor array are processed by a decision circuit which generates a final character recognition signal. A character presence processor searches for a vertical path between character segments to indicate the presence of a character by locating the beginnings and endings of characters. For certain unique characters having vertical gaps between portions of the character a means is provided within the character presence unit to indicate that the vertical gap is to be ignored and that a character code is not to be transferred to the decision circuit.