data augmentation for video segmentation
http://qw5w9m21j.hn-bkt.clouddn.com/toy_data.zip
https://drive.google.com/file/d/1VLY6Ob0pPlCPHopWp68c43UnG0zBLcHS/view?usp=sharing
python3 copy_paste.py --src_dir=.../toy_data --target_dir=.../copy_paste
python3 copy_paste_same.py --src_dir=.../toy_data --target_dir=.../copy_paste_same --num_worker=4