How To Install OpenCV on CentOS 7

In this tutorial, we will show you how to install OpenCV on CentOS 7. For those of you who didn’t know, OpenCV (Open Source Computer Vision Library) is an open-source, highly optimized computer library mainly used in applications for image processing. It has a variety of inbuilt image processing functions helping you to get started easily. It runs on Linux, Windows, Mac OS, iOS, and Android.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of OpenCV on a CentOS 7 server.

Prerequisites

• A server running one of the following operating systems: CentOS 7.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install OpenCV on CentOS 7

Step 1. First, let’s start by ensuring your system is up-to-date.

yum clean all
yum -y update

Step 2. Installing dependencies for OpenCV.

Use the following commands to install all required dependencies for compiling OpenCV:

yum groupinstall "Development Tools"
yum install cmake gcc gtk2-devel numpy pkconfig

Step 3. Installing OpenCV on CentOS 7.

First, Download and unarchive the OpenCV archive as below:

wget https://github.com/opencv/opencv/archive/3.3.0.zip
unzip 3.3.0.zip

Next, we compile and install OpenCV:

cd opencv-3.3.0
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=DEBUG -D CMAKE_INSTALL_PREFIX=/usr/local ..
make
make install

Then, configure the required variables:

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig/
echo '/usr/local/lib/' >> /etc/ld.so.conf.d/opencv.conf
ldconfig

To test your OpenCV installation, you can download extra test data from the OpenCV extra repository:

cd
git clone https://github.com/opencv/opencv_extra.git
export OPENCV_TEST_DATA_PATH=/root/opencv_extra/testcinta

In the CMake build directory, you will find several test executables named in the same kind of format opencv_test_*. Run anyone you are interested in to perform a test. Example below:

cd /root/opencv-3.3.0/build/bin
ls
./opencv_test_cinta

Congratulations! You have successfully installed OpenCV. Thanks for using this tutorial for installing OpenCV on CentOS 7 system. For additional help or useful information, we recommend you to check the official OpenCV website.