Refinement and testing of a character recognition system based on feature extraction in grayscale space

A method for recognizing degraded text is described. One application domain is postal address blocks, where the system must function with varying and unspecified fonts, dot matrix printing, and poor print quality. The design achieves tolerance to differing contrast and degraded print via gray-scale analysis, and omnifont capability and good performance on touching and broken characters by encoding character shapes as graphs. Experimental results on address blocks supplied by the US Postal Service are presented. Experiments on subsampling the data indicate that the performance at 100 dpi is very close to that of the original 300 dpi