Understanding mathematical expressions in a printed document

A system for understanding mathematical expressions is presented. After separating all symbols in an input mathematical expression, we utilize thirteen features to represent each symbol. In order to reduce the computational time, a coarse classification algorithm is used to reduce the number of candidates. Then for each input symbol, the character with the highest similarity is selected as the candidate symbol. Since some of the symbols in an arithmetical expression may touch each other, a dynamic programming algorithm is adopted to identify correct characters from connected symbols. In the expression formation stage, a procedure-oriented method is proposed for translating the recognized symbols appearing in a 2D space into a 1D character string. The authors have used 105 mathematical expressions as training data and 50 expressions as testing data. The experimental results have demonstrated the feasibility of the understanding system