How To Install OpenCV On CentOS 8

Insight: How To Install OpenCV On CentOS 8

OpenCV or Open Source Computer Vision Library is an open-source computer vision library. In this tutorial post, we are going to show you the process of installing OpenCV on CentOS 8.

How To Install OpenCV On CentOS 8

Install OpenCV from the CentOS Repository

The OpenCV packages are available from the CentOS 8 standard repositories. Run the following command to install the OpenCV packages by typing:

sudo dnf install opencv opencv-devel opencv-python

Now verify that OpenCV library exists by running:

pkg-config --modversion opencv

Installing OpenCV from the Source

Install the required and optional dependencies:

sudo dnf install epel-release git gcc gcc-c++ cmake3 qt5-qtbase-devel \ python3 python3-devel python3-pip cmake python3-devel python3-numpy \    gtk2-devel libpng-devel jasper-devel openexr-devel libwebp-devel \    libjpeg-turbo-devel libtiff-devel tbb-devel libv4l-devel \    eigen3-devel freeglut-devel mesa-libGL mesa-libGL-devel \    boost boost-thread boost-devel gstreamer1-plugins-base

Clone both OpenCV’s and OpenCV contrib repositories:

mkdir -p ~/opencv_build && cd ~/opencv_buildgit clone https://github.com/opencv/opencv.gitgit clone https://github.com/opencv/opencv_contrib.git

Create a temporary build directory, and switch to it:

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

Run the CMake command:

cmake3 -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 ..

Compile using the following command:

make -j8

note: Modify the -j flag according to your processor.

Install the OpenCV libraries with:

sudo make install

Create symlink opencv4.pc file to the /usr/share/pkgconfig directory and run ldconfig to rebuild the libraries cache.

sudo ln -s /usr/local/lib64/pkgconfig/opencv4.pc /usr/share/pkgconfig/sudo ldconfig