ON THE REJECTION ABILITY REQUIRED IN MULTIPLE HYPOTHESIS TECHNIQUES

Abstract

Microsoft, Motorola, Siemens, Hitachi, IAPR, NICI, IUF The so­called multiple hypothesis technique is applied to solve a recognition problem that can be divided into at least two sub­problems. The principle of the technique is to solve the sub­problems by recognisers, a pre­recogniser and a post­recogniser, and to allow the pre­recogniser to leave several possible solutions to the post­recogniser. The pre­recogniser uses several hypotheses based on information or a priori knowledge. The post­recogniser tries to solve its assigned sub­problem by using the solutions from the pre­recogniser and different a priori knowledge. Therefore, there must be co­operation between the recognisers in order to achieve better total performance in solving the recognition problem. In this study, required abilities of the pre­ and the post­recognisers are analysed in order to attain better recognition performance. This analysis gives guidelines for two special factors: number of outputs of the pre­recogniser and required recognition rate of each recogniser. These guidelines are applied to an actual mail­address reading system using a multiple hypothesis technique