OpenCV is a library of programming functions mainly aimed at real-time computer vision. Originally developed by Intel, it was later supported by Willow Garage then Itseez. The library is cross-platform and free for use under the open-source BSD license. This video shows how to install OpenCV on Ubuntu.
The commands that have been used in this video are as follows:
$ sudo apt-get update
$ sudo apt-get install python-pip
OR
$ sudo apt-get install python3-pip