OpenCV Installation

From the Ubuntu Repository

1. Installation

   sudo apt update
   sudo apt install python3-opencv
   

2. Verify

   python3 -c "import cv2; print(cv2.__version__)"
   

From Source

1. Install dependencies

   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-dev
   

2. Clone repos

   mkdir ~/opencv_build && cd ~/opencv_build
   git clone https://github.com/opencv/opencv.git
   git clone https://github.com/opencv/opencv_contrib.git
   

3. Create a temporary build directory

   cd ~/opencv_build/opencv
   mkdir build && cd build
   

Set up build with 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_build/opencv_contrib/modules \
-D BUILD_EXAMPLES=ON ..

4. Start the compilation process

   make -j8
   

If you do not know the number of cores your processor, you can find it by typing nproc

5. Install OpenCV

   sudo make install
   

6. Verify

   pkg-config --modversion opencv4
   python3 -c "import cv2; print(cv2.__version__)"