Prepare datasets according to the guidelines in [MMDetection v2.28.1](https://github.com/open-mmlab/mmdetection/blob/master/docs/en/1_exist_data_model.md).
Prepare COCO according to the guidelines in [MMDetection v2.28.1](https://github.com/open-mmlab/mmdetection/blob/master/docs/en/1_exist_data_model.md).