Experiments with an n-tuple recogniser for fast `first try´ recognition of unconstrained handwritten symbols

The recognition of relatively unconstrained handwritten characters using the n-tuple recognition technique in two application areas is reported. In the case of Electronic Paper, a high resolution flat panel display with a transparent digitizer on its surface, the character set consists of 73 distinct characters and in the case of British postcodes the character set consists of 36 distinct characters. The technique is investigated as a fast method of producing a ranked list of likely classes for each character. The results presented conclude that the n-tuple recognizer is capable of achieving approximately 60% correct first-choice classification on totally unconstrained handwritten characters from any writer and over 90% correct first-choice classification on unconstrained handwritten characters from one writer if the class size is between 15 and 20. In cases where the actual character is not at the top of the ranked list it is usually in a high-ranked position. Recognition performance deteriorates rapidly as the class size exceeds 20