Structure analysis and recognition of mathematical expressions

A wide variety of mathematical expressions printed in documents can be recognized by analyzing the two-dimensional layout structures of the symbols within the expressions. Our method consists of two basic strategies. One is a specific structure analysis where local structures of subexpressions are checked by a bottom-up method. The other is a basic structure analysis in which the global structure of a whole expression is checked by using a top-down method. The structure of a recognized expression is represented by a tree structure and the original expression can be reproduced by using a suitable formatter like T_EX. Experiments have been carried out for many types of expressions found in printed journals and our recognition method has shown favorable results