Multi-scale Cell-based Layout Representation for Document Understanding

Deep learning techniques have achieved remarkable progress in document understanding. Most models use co-ordinates to represent absolute or relative spatial information of components, but they are difficult to represent latent rules in the document layout. This makes learning layout representation to be more difficult. Unlike the previous researches which have employed the coordinate system, graph or grid to represent the document layout, we propose a novel layout representation, the cell-based layout, to provide easy-to-understand spatial information for backbone models. In line with human reading habits, it uses cell information, i.e. row and column index, to represent the position of components in a document, and makes the document layout easier to understand. Furthermore, we proposed the multi-scale layout to represent the hierarchical structure of layout, and developed a data augmentation method to improve the performance. Experiment results show that our method achieves the state-of-the-art performance in text-based tasks, including form understanding and receipt understanding, and improves the performance in image-based task such as document image classification. We released the code in the repoa.