Precise detection of Chinese characters in historical documents with deep reinforcement learning.

•We propose precise detection of Chinese characters using a deep reinforcement learning framework to obtain tighter bounding boxes under large IoU.•We propose a new PSRoI pooling method and a new dense reward function.•The proposed deep reinforcement learning framework combines the advantages of three variants of Deep Q-Networks.•Our method achieves state-of-the-art results on several Chinese historical document datasets.