Install OpenCV-Python in Ubuntu

Note: Please prefer binaries distributed with PyPI, if possible. See Install OpenCV with pip for details.

Goals

We will learn to setup OpenCV-Python in Ubuntu System. Below steps are tested for Ubuntu 16.04 and 18.04 (both 64-bit).

Method 1: Install from Pre-built Binaries

This method serves best when using just for programming and developing OpenCV applications.

sudo apt-get install python3-opencv

Open Python IDLE (or IPython) and type following codes in Python terminal:

import cv2 as cv
print(cv.__version__)

If the results are printed out without any errors, congratulations! You have installed OpenCV-Python successfully.

Note: Apt repositories may not contain the latest version of OpenCV always. For getting latest source codes, use the next method (building from source).

Method 2: Building OpenCV from Source

Compiling from source may seem a little complicated at first, but once you succeeded in it, there is nothing complicated.

Required Build Dependencies

sudo apt-get install cmake
sudo apt-get install gcc g++

# For Python 3 support:
sudo apt-get install python3-dev python3-numpy

# For GUI features, Camera support, and Media Support:
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev
sudo apt-get install libgstreamer-plugins-base1.0-dev libgstreamer1.0-dev

# For GTK 3 support:
sudo apt-get install libgtk-3-dev

Optional Dependencies

sudo apt-get install libpng-dev
sudo apt-get install libjpeg-dev
sudo apt-get install libopenexr-dev
sudo apt-get install libtiff-dev
sudo apt-get install libwebp-dev

Downloading OpenCV

sudo apt-get install git
git clone https://github.com/opencv/opencv.git

Configuring and Installing

cd opencv
mkdir build
cd build
cmake ../
make
sudo make install

Installation is over. All files are installed in /usr/local/ folder. Open a terminal and try importing cv2:

import cv2 as cv
print(cv.__version__)

Source: OpenCV Python Tutorials — Original Documentation