In this post we will see How to Install OpenCV in Ubuntu for C/C++
OpenCV is an image processing library created by Intel and later supported by Willow Garage and now maintained by Itseez. OpenCV means Intel® Open Source Computer Vision Library. It is a collection of C functions and a few C++ classes that implement some popular Image Processing and Computer Vision algorithms. OpenCV is Available on Mac, Windows, Linux (Terminal environment).
Step 1 – Updating Ubuntu
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$ sudo apt-get update $ sudo apt-get upgrade |
Step 2 – Install dependencies
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$ sudo apt-get install build-essential cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev $ sudo apt-get install python3.5-dev python3-numpy libtbb2 libtbb-dev $ sudo apt-get install libjpeg-dev libpng-dev libtiff5-dev libjasper-dev libdc1394-22-dev libeigen3-dev libtheora-dev libvorbis-dev libxvidcore-dev libx264-dev sphinx-common libtbb-dev yasm libfaac-dev libopencore-amrnb-dev libopencore-amrwb-dev libopenexr-dev libgstreamer-plugins-base1.0-dev libavutil-dev libavfilter-dev libavresample-dev |
Step 3 – Get OpenCV
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$ sudo -s $ cd /opt /opt$ git clone https://github.com/Itseez/opencv.git /opt$ git clone https://github.com/Itseez/opencv_contrib.git |
Step 4 – build and install OpenCV
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/opt$ cd opencv /opt/opencv$ mkdir release /opt/opencv$ cd release /opt/opencv/release$ cmake -D BUILD_TIFF=ON -D WITH_CUDA=OFF -D ENABLE_AVX=OFF -D WITH_OPENGL=OFF -D WITH_OPENCL=OFF -D WITH_IPP=OFF -D WITH_TBB=ON -D BUILD_TBB=ON -D WITH_EIGEN=OFF -D WITH_V4L=OFF -D WITH_VTK=OFF -D BUILD_TESTS=OFF -D BUILD_PERF_TESTS=OFF -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D OPENCV_EXTRA_MODULES_PATH=/opt/opencv_contrib/modules /opt/opencv/ /opt/opencv$ make -j4 /opt/opencv$ make install /opt/opencv$ ldconfig /opt/opencv$ exit /opt/opencv$ cd ~ |
Now to check if OpenCV is installed on a machine, run the following commands
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$ pkg-config --modversion opencv 3.2.x |
We will get the opencv version installed
in this case it’s 3.2.x
Create a C++ program
Follow the commands
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$ mkdir cpp_test $ cd cpp_test $ touch main.cpp |
The above command will create a folder called cpp_test and create a main.cpp file inside it
Now place any .jpeg image inside the cpp_test folder.
So Now your cpp_test folder will contain two files as follows
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├── sample.jpeg
└── main.cpp
Now open the main.cpp and add the following code
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#include <opencv2/highgui.hpp> #include <iostream> int main( int argc, char** argv ) { cv::Mat image; image = cv::imread("sample.jpeg" , CV_LOAD_IMAGE_COLOR); if(! image.data ) { std::cout << "Could not open or find the image" << std::endl ; return -1; } cv::namedWindow( "Display window", cv::WINDOW_AUTOSIZE ); cv::imshow( "Display window", image ); cv::waitKey(0); return 0; } |
Now compile your code with the following command
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g++ main.cpp -o output `pkg-config --cflags --libs opencv` |
Now run the C++ program with the following command
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$ ./output |
press ESC to exit
Video instruction – How to Install OpenCV in Ubuntu 16.04 LTS for C / C++