  Text is ubiquitous in our visual world, conveying crucial information, such
as in documents, websites, and everyday photographs. In this work, we propose
UReader, a first exploration of universal OCR-free visually-situated language
understanding based on the Multimodal Large Language Model (MLLM). By
leveraging the shallow text recognition ability of the MLLM, we only finetuned
1.2% parameters and the training cost is much lower than previous work
following domain-specific pretraining and finetuning paradigms. Concretely,
UReader is jointly finetuned on a wide range of Visually-situated Language
Understanding tasks via a unified instruction format. To enhance the visual
text and semantic understanding, we further apply two auxiliary tasks with the
same format, namely text reading and key points generation tasks. We design a
shape-adaptive cropping module before the encoder-decoder architecture of MLLM
to leverage the frozen low-resolution vision encoder for processing
high-resolution images. Without downstream finetuning, our single model
achieves state-of-the-art ocr-free performance in 8 out of 10 visually-situated
language understanding tasks, across 5 domains: documents, tables, charts,
natural images, and webpage screenshots. Codes and instruction-tuning datasets
will be released.
