method: CLOVA OCR2019-05-02

Authors: Sungrae Park, Seonghyeon Kim, Seung Shin, Jaeheung Surh, Junyeop Lee, Hwalsuk Lee

Description: A sequence tagging approach classifying tokens in all text boxes.
We used the pre-trained BERT model and finetuned the model to classify all tokens into 5 classes such as "none", "company", "address", "date", and "total". In order to feed a single text sequence, we identified lines in a receipt, sorted text boxes at each line, and merged them line by line.