Build opencv4.0.1 & opencv_contrib on Windows

• Install Visual Studio 2019
• Install Cmake https://cmake.org/download/
• Prepare sources of OpenCV Version 4.0.1

— Download opencv source: https://github.com/opencv/opencv/releases

— Download opencv_contrib source: https://github.com/opencv/opencv_contrib/releases

• Extract both to the same folder
• Run Cmake-GUI