If you don't know the Guess The Correlation Game, [go there](http://guessthecorrelation.com/) and play it for a while.

If you don't know what (Linear) Correlation is, [go to wiki](https://en.wikipedia.org/wiki/Correlation_coefficient) to have some clue about what it is.

The goal is: build a function that, given an image containing of a scatterplot, it returns the respective linear correlation coefficient of it. 

Have fun!