Recognizing Handwritten Mathematical Expressions of Vertical Addition and Subtraction

  • Daniel Rosa UFRPE
  • Filipe R. Cordeiro UFRPE
  • Ruan Carvalho UFRPE
  • Everton Souza UFRPE
  • Sergio Chevtchenko UFPE
  • Luiz Rodrigues UFAL
  • Marcelo Marinho UFRPE
  • Thales Vieira UFAL
  • Valmir Macario UFRPE

Resumo


Handwritten Mathematical Expression Recognition (HMER) is a challenging task with many educational applications. Recent methods for HMER have been developed for complex mathematical expressions in standard horizontal format. However, solutions for elementary mathematical expression, such as vertical addition and subtraction, have not been explored in the literature. This work proposes a new handwritten elementary mathematical expression dataset composed of addition and sub-traction expressions in a vertical format. We also extended the MNIST dataset to generate artificial images with this structure. Furthermore, we proposed a solution for offline HMER, able to recognize vertical addition and subtraction expressions. Our analysis evaluated the object detection algorithms YOLO_v7, YOLO_v8, YOLO-NAS, NanoDet and FCOS for identifying the mathematical symbols. We also proposed a transcription method to map the bounding boxes from the object detection stage to a mathematical expression in the LaTeX markup sequence. Results show that our approach is efficient, achieving a high expression recognition rate. The code and dataset are available at https://github.com/Danielgol/HME-VAS.

Publicado
06/11/2023
ROSA, Daniel et al. Recognizing Handwritten Mathematical Expressions of Vertical Addition and Subtraction. In: CONFERENCE ON GRAPHICS, PATTERNS AND IMAGES (SIBGRAPI), 36. , 2023, Rio Grande/RS. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2023 . p. 73-78.