Implement the visual system

[WoutervdW]

Make a class that can detect motion and quantifies the amount of movement in the image (using OpenCV (https://hardikmadhu.blogspot.nl/2013/09/a-simple-and-minimal-aproach-to-human.
html))

"The visual system of the robot will be implemented using the Python library
OpenCV (https://hardikmadhu.blogspot.nl/2013/09/a-simple-and-minimal-aproach-to-human.
html). Using this library, we can do motion tracking using the camera images of
the NAO, in order to calculate the amount of movement in the mobile. We will
measure how much the image changes from moment to moment. This amount
of movement will be sent to the comparator and the reward center."