  Text images contain both visual and linguistic information. However, existing
pre-training techniques for text recognition mainly focus on either visual
representation learning or linguistic knowledge learning. In this paper, we
propose a novel approach MaskOCR to unify vision and language pre-training in
the classical encoder-decoder recognition framework. We adopt the masked image
modeling approach to pre-train the feature encoder using a large set of
unlabeled real text images, which allows us to learn strong visual
representations. In contrast to introducing linguistic knowledge with an
additional language model, we directly pre-train the sequence decoder.
Specifically, we transform text data into synthesized text images to unify the
data modalities of vision and language, and enhance the language modeling
capability of the sequence decoder using a proposed masked image-language
modeling scheme. Significantly, the encoder is frozen during the pre-training
phase of the sequence decoder. Experimental results demonstrate that our
proposed method achieves superior performance on benchmark datasets, including
Chinese and English text images.
