An Improved Analysis Approach of Overbrace/Underbrace Structure in Printed Mathematical Expressions
In printed mathematical expression recognition, structural analysis is a key step which determines the overall recognition results. As a special structure in expressions, overbrace/underbrace structure becomes a major difficulty of structural analysis as they’re difficult to be distinguished from other structures. On the basis of baseline analysis method of expression structures, this paper presents an improved approach of overbrace/underbrace structure combining region location with variable thresholds. This approach introduces overrun threshold of overbrace/underbrace symbol, which is combined with other features to establish the analysis rules and optimized by testing on a variety of overbrace/underbrace structures. The experimental results show that the approach is effective in determining and analyzing overbrace/underbrace structure.