tutorial-opencv.txt

Step 1. Update the Ubuntu System Package
sudo apt-get update && sudo apt-get upgrade
sudo apt install software-properties-common apt-file

Step 2. Install Required tools and packages 
sudo apt-get install build-essential cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
sudo apt-add-repository ppa:deadsnakes/ppa
$ sudo apt-get install python3.5-dev python3-numpy libtbb2 libtbb-dev

sudo apt-add-repository "deb http://security.ubuntu.com/ubuntu xenial-security main"
sudo apt update
sudo apt install libjasper1 libjasper-dev

Step 3. Download OpenCV Sources using git
sudo -s
cd ~ && cd /opt
git clone https://github.com/Itseez/opencv.git
git clone https://github.com/Itseez/opencv_contrib.git

Step 4. Build & Install OpenCV 
cd opencv
mkdir release
cd 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 OPENCV_GENERATE_PKGCONFIG=ON -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D OPENCV_EXTRA_MODULES_PATH=/opt/opencv_contrib/modules /opt/opencv/
make -j4
make install
ldconfig
exit
cd ~

Step 5. Check OpenCV version installed
apt-file search opencv.pc
ls /usr/local/lib/pkgconfig/
sudo cp /usr/local/lib/pkgconfig/opencv4.pc  /usr/lib/x86_64-linux-gnu/pkgconfig/opencv.pc
pkg-config --modversion opencv


ref : http://techawarey.com/programming/install-opencv-c-c-in-ubuntu-18-04-lts-step-by-step-guide/