Writer adaptation improves recognition of handwritten math expressions

Cross-Domain Few-Shot Writer Adaptation for Real-World Handwritten Mathematical Expression Recognition

Computer Vision and Pattern Recognition

Summary

Recognizing handwritten math is hard, especially when someone writes in their own style or when the images are taken by a camera, not scanned perfectly. The authors study these challenges and create a way to adjust an existing math recognition system for different writers. Their approach helps the system better understand digital handwriting and some camera images, though results vary depending on the writing and image quality. This shows that customizing math recognition to individual writers can work in practice.

What this means in practice

  • For math software developers: Improve handwritten math input tools by fine-tuning recognition models to individual users’ handwriting styles.
  • For mobile app developers: Enhance math recognition in camera-captured handwriting apps by adapting models to different handwriting styles on the fly.

Authors

Paulo Grane Gabriel Silva, Lorenz Bernard Marqueses, Joel Ilao

Abstract

Handwritten mathematical expression recognition (HMER) refers to the task of recognizing and converting handwritten mathematics into a parsable markup language, usually LaTeX. No current state-of-the-art-competitive system adjusts to the way a specific person writes, and the domain gap between training images (usually digital or perfectly binarized) and images physically taken with a camera used in inference has received fairly little attention for this specific problem. We characterize this domain gap through fragmentation and stroke-width analyses of the images as well as introduce a writer-adaptive fine-tuning pipeline to MFH-CoMER in an attempt to address it. We further introduce sample author-specific datasets, consisting of five handwriting category subsets from two authors, and evaluate using a McNemar's test and permutation tests adapted to limited data. Results suggest an increase in expression recognition rate and a decrease in CER for digital handwriting but more varied results for physical handwriting, with the model struggling for handwriting articles that the base model can already evaluate well. Nonetheless, adapted models were found to have improved results for four out of five subsets. Statistical testing results suggest a consistency in improvement for two of the tested author-specific subsets. Our results point towards the potential feasibility of writer adaptation for the HMER task.