Robustness Evaluation of Transformer-Based Form Field Extractors via Form Attacks

Abstract

We propose a novel framework to evaluate the robustness of transformer-based form field extraction methods via form attacks. We introduce 14 novel form transformations to evaluate the vulnerability of the state-of-the-art field extractors against form attacks from both OCR level and form level, including OCR location/order rearrangement, form background manipulation and form field-value augmentation. We conduct robustness evaluation using real invoices and receipts, and perform comprehensive research analysis. Experimental results suggest that the evaluated models are very susceptible to form perturbations such as the variation of field-values ($\sim$ 15% drop in F1 score), the disarrangement of input text order($\sim$ 15% drop in F1 score) and the disruption of the neighboring words of field-values($\sim$ 10% drop in F1 score). Guided by the analysis, we make recommendations to improve the design of field extractors and the process of data collection. Code will be available at here.