DESIGN OF A HANDPRINT RECOGNITION SYSTEM

A public domain optical character recognition (OCR) system has been de veloped by the National institute of Standards and Technology (NIST). This standard reference form-based handprint recognition system is des igned to provide a baseline of performance on an open application. The system's source code, training data, performance assessment tools, an d type of forms processed are all publicly available. The system is mo dular, allowing for system component testing and comparisons, and it c an be used to validate training and testing sets in an end-to-end appl ication. The system's source code is written in C and will run on virt ually any UNIX-based computer. The presented functional components of the system are divided into three levels of processing: (1) form-level processing in eludes the tasks of form registration and form removal; (2) field-level processing includes the tasks of field isolation, lin e trajectory reconstruction, and field segmentation; and (3) character -level processing includes character normalization, feature extraction , character classification, and dictionary-based postprocessing. The s ystem contains a number of significant contributions to OCR technology , in eluding an optimized probabilistic neural network (PNN) classifie r that operates a factor of 20 times faster than traditional software implementations of the algorithm. Provided in the system are a host of data structures and low-level utilities for computing spatial histo g rams, least-squares fitting, spatial zooming, connected components, Ka rhunen Loeve feature extraction, optimized PNN classification, and dyn amic string alignment. Any portion of this standard reference OCR syst em can be used in commercial products without restrictions, (C) 1997 S PIE and IS&T. [S1017-9909(97)00502-3].