###### tags: `linux`

# Ubuntu 20.04 LTS 編譯 OpenCV 4.5.0

+ ## 環境
+ `ubuntu 20.04 LTS`

+ ## 相依套件安裝

sudo apt install build-essential -y
sudo apt install pkg-config -y

sudo apt install libjpeg-dev libtiff5-dev libjasper-dev libpng12-dev -y
sudo apt install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev -y
sudo apt install libxvidcore-dev libx264-dev libgtk2.0-dev libgtk-3-dev -y
sudo apt install libcanberra-gtk* -y
sudo apt install libatlas-base-dev gfortran -y

sudo apt install python-dev python-pip -y
sudo pip install --upgrade pip
sudo pip install numpy

sudo apt install python3-dev python3-pip -y
sudo pip3 install --upgrade pip
sudo pip3 install numpy

sudo apt install --reinstall linux-libc-dev

> [get manually removed header file](https://askubuntu.com/a/1264013)

+ ## 下載原始碼

mkdir -p ~/library/
cd ~/library && git clone https://github.com/opencv/opencv

+ ## 錯誤修正

sudo cp /usr/include/x86_64-linux-gnu/sys/io.h /usr/include

+ ## 編譯

git checkout 4.5.0
mkdir -p ~/library/opencv/build

cmake -D CMAKE_BUILD_TYPE=Release \
-D CMAKE_INSTALL_PREFIX=/usr/local \
-D BUILD_EXAMPLES=ON \
-D BUILD_TESTS=OFF \
-D INSTALL_C_EXAMPLES=OFF \
-D INSTALL_PYTHON_EXAMPLES=OFF \
-D BUILD_opencv_python3=ON \
-D PYTHON3_INCLUDE_DIR=/usr/include/python3.8 \
-D PYTHON3_LIBRARY=/usr/lib/python3.8/config-3.8-x86_64-linux-gnu/libpython3.8.so ..
make -j`nproc`

+ ## 安裝至系統

sudo make install -j`nproc`