create -n opencv_env python=3.8
conda activate opencv_env
python -m pip install opencv-python -i https://pypi.tuna.tsinghua.edu.cn/simple --trusted-host pypi.tuna.tsinghua.edu.cn
python -m pip install opencv-contrib-python -i https://pypi.tuna.tsinghua.edu.cn/simple --trusted-host pypi.tuna.tsinghua.edu.cn