OpenCV 4 Example

Prerequisites

You need to install some dependencies on your system before installing OpenCV4

sudo apt install build-essential cmake git pkg-config libgtk-3-dev \
    libavcodec-dev libavformat-dev libswscale-dev libv4l-dev \
    libxvidcore-dev libx264-dev libjpeg-dev libpng-dev libtiff-dev \
    gfortran openexr libatlas-base-dev python3-dev python3-numpy \
    libtbb2 libtbb-dev libdc1394-22-dev

Install OpenCV4 from source

This example suppose that you have installed Ubuntu 18.04 on your dev machine. You need the SIFT implementation to run this code...

You need to install the missing non-free version of OpenCV4. To do that type the following in the terminal:

# First cd into where you want to put the Opencv library, e.g ~/dev/libs/
mkdir -p ~/dev/libs && cd ~/dev/libs/
git clone https://github.com/opencv/opencv.git -b 4.3.0
git clone https://github.com/opencv/opencv_contrib.git -b 4.3.0
mkdir opencv/build && cd opencv/build
cmake -DOPENCV_EXTRA_MODULES_PATH=../../opencv_contrib/modules ..
make -j$(nproc --all) && sudo make install

How to Build the examples on this repository

Build is straightforward:

mkdir build/
cd build/
cmake ..
make