ubuntu下卸载opencv步骤
1. 进入build文件夹，命令行执行make uninstall
2. cd ..
3. sudo rm -r build
4. sudo rm -r /usr/local/include/opencv2 /usr/local/include/opencv /usr/include/opencv /usr/include/opencv2 /usr/local/share/opencv /usr/local/share/OpenCV /usr/share/opencv /usr/share/OpenCV /usr/local/bin/opencv* /usr/local/lib/libopencv*
安装相关依赖库（相关依赖库一定得装上，否则后果自负）
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install build-essential cmake pkg-config
sudo apt-get install libjpeg8-dev libtiff5-dev libjasper-dev libpng12-dev
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
sudo apt-get install libxvidcore-dev libx264-dev
sudo apt-get install libgtk-3-dev
sudo apt-get install libatlas-base-dev gfortran
sudo apt-get install python3.5-dev
执行cmake命令
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D PYTHON3_EXECUTABLE=/usr/bin/python3 -D PYTHON3_INCLUDE_DIR=/usr/include/python3.5 -D PYTHON3_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython3.5m.so -D PYTHON3_NUMPY_INCLUDE_DIRS=/usr/local/lib/python3.5/dist-packages/numpy/core/include -D WITH_FFMPEG=ON -D WITH_TBB=ON -D WITH_GTK=ON -D WITH_LIBV4L=ON ..
执行编译命令
make -j8
执行安装命令
sudo make install
加入到动态链接库
sudo ldconfig
查看是否支持FFMPEG
python -c "import cv2; print(cv2.getBuildInformation())" | grep -i ffmpeg
输出FFMPEG: YES才是正确的
查看opencv版本
pkg-config --modversion opencv