[ubuntu18] opencv

ubuntu18_opencv

$ sudo apt update
$ sudo apt install python3-opencv


$ sudo apt install build-essential cmake git pkg-config libgtk-3-dev
$ sudo apt install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev libxvidcore-dev libx264-dev
$ sudo apt install libjpeg-dev libpng-dev libtiff-dev gfortran openexr libatlas-base-dev
$ sudo apt install python3-dev python3-numpy libtbb2 libtbb-dev libdc1394-22-de

$ mkdir ~/opencv_build && cd ~/opencv_build
$ git clone https://github.com/opencv/opencv.git
$ git clone https://github.com/opencv/opencv_contrib.git
如果要安装旧版本的OpenCV，请在opencv和opencv_contrib目录运行git checkout <opencv-version>
ex. git checkout 3.4.4

copy opencv_contrib to opencv folder, and then cmake
$ cmake -D CMAKE_BUILD_TYPE=RELEASE \
    -D CMAKE_INSTALL_PREFIX=/usr/local \
    -D INSTALL_C_EXAMPLES=ON \
    -D INSTALL_PYTHON_EXAMPLES=ON \
    -D OPENCV_GENERATE_PKGCONFIG=ON \
    -D OPENCV_EXTRA_MODULES_PATH=../opencv_contrib/modules \
    -D BUILD_EXAMPLES=ON ..
    
$ make -j8
$ sudo make install

check version of opencv
$ pkg-config --modversion opencv or pkg-config --modversion opencv4