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.

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

How To Install OpenCV On CentOS 8