源码安装 OpenCV 4.5
官方文档：
OpenCV: Install OpenCV-Python in Ubuntu
1. 安装编译依赖
sudo apt install build-essential cmake git pkg-config libgtk-3-dev \ libavcodec-dev libavformat-dev libswscale-dev libv4l-dev \ libxvidcore-dev libx264-dev libjpeg-dev libpng-dev libtiff-dev \ gfortran openexr libatlas-base-dev python3-dev python3-numpy \ libtbb2 libtbb-dev libdc1394-22-dev2. 克隆 OpenCV 4.5.0 源代码
wget -O opencv.zip https://github.com/opencv/opencv/archive/4.5.0.zip
wget -O opencv.zip https://github.com/opencv/opencv/archive/master.zip3. 编译 OpenCV
mkdir buildcd buildcmake -DCMAKE_BUILD_TYPE=Release \
-DCMAKE_INSTALL_PREFIX=/usr/local/opencv \
-DINSTALL_PYTHON_EXAMPLES=OFF \
-DINSTALL_C_EXAMPLES=OFF \
-DBUILD_EXAMPLES=OFF \
-DBUILD_TEST=OFF \
-DENABLE_FAST_MATH=1 \
-DOPENCV_ENABLE_NONFREE=ON \
..make -j4 # 使用 4 核处理器来编译sudo make install第一次直接make -j8的时候，报 test 相关的错误，增加上述关闭 test 的 cmake 参数，删除 build 文件夹，重新编译，仍然报
4. 编辑/etc/ld.so.conf
include /etc/ld.so.conf.d/*.conf
include /usr/local/lib
sudo ldconfig
5. 编辑bash .bashrc
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig export PKG_CONFIG_PATH
参考文章：
Ubuntu 20.04 LTS 安装OpenCV 4.5.5-CSDN博客
