Many articles here and there describe how to use OpenCV on Raspberry Pi. However, most of them are about setting up the environment by hand — meaning compiling OpenCV from sources. There are two main disadvantages to this approach. Firstly, you have to spend some time to compile it. On Raspberry Pi 3 it takes quite some time, and not mentioning the earlier versions of this mini PC. Secondly, maintaining up–to–date version requires additional time. Still, you can go for middle ground — cross–compilation that requires less time but you have to set up the environment properly. Having above in mind I will introduce you to the OpenCV with Python interface installed from pre–compiled packages. If I have your attention keep reading 😉