cmake -D CMAKE_BUILD_TYPE=RELEASE \
      -D CMAKE_INSTALL_PREFIX=/usr/local \
      -D INSTALL_PYTHON_EXAMPLES=ON \
      -D INSTALL_C_EXAMPLES=OFF \
      -D OPENCV_EXTRA_MODULES_PATH=~/Downloads/Deeplearning/opencv_contrib-3.4.2/modules \
      -D PYTHON3_EXECUTABLE='~/anaconda3/envs/opencv/bin/python' \
      -D PYTHON_INCLUDE_DIR='~/anaconda3/envs/opencv/include/python3.6m' \
      -D PYTHON3_LIBRARY='~/anaconda3/envs/opencv/lib/libpython3.6m.so' \
      -D PYTHON_EXECUTABLE='~/anaconda3/envs/opencv/bin/python' \
      -D PYTHON3_NUMPY_INCLUDE_DIRS='~/anaconda3/envs/opencv/lib/python3.6/site-packages/numpy/core/include' \
      -D PYTHON3_PACKAGES_PATH='~/anaconda3/envs/opencv/lib/python3.6/site-packages' \
      -D BUILD_EXAMPLES=ON -D BUILD_NEW_PYTHON_SUPPORT=ON ..