git clone https://github.com/opencv/opencv.git
cd opencv-4.2.0/ mkdir build cd build/ cmake -D CMAKE_BUILD_TYPE=RELEASE -D OPENCV_GENERATE_PKGCONFIG=ON -D CMAKE_INSTALL_PREFIX=/usr/local .. make -j8 sudo make install
git clone https://github.com/opencv/opencv.git
cd opencv-4.2.0/ mkdir build cd build/ cmake -D CMAKE_BUILD_TYPE=RELEASE -D OPENCV_GENERATE_PKGCONFIG=ON -D CMAKE_INSTALL_PREFIX=/usr/local .. make -j8 sudo make install