Recognition of damaged letters based on mathematical fuzzy logic analysis

This paper reports a real application whose task was to recognize characters printed on metal ingots. The problem is that surface of ingots is very uneven — ingots are hot or cold, cut by rough instrument, the printing machine can be worn down, etc. In this paper, we present two original recognition methods: the first one is based on application of mathematical fuzzy logic and the second one is based on representation of an image by a fuzzy-valued function. Results of these methods are compared with a simple neural network classifier and few other common methods.