Design of a mathematical expression recognition system

We present a system to segment and recognize texts and mathematical expressions in a document. The system can be divided into six stages: page segmentation and labeling, character segmentation, feature extraction, character recognition, expression formation, and error correction and expression extraction. In expression formation, we build a symbol relation tree for each text line to represent the relationships among the symbols in the text line. Some heuristic rules based on the primitive tokens are used to correct the recognition errors in a text line. We extract all mathematical expressions according to some basic expression forms. Our database consists of 190 symbols in the current stage. The average recognition rate is about 96.16%.