Can someone guide me how can I solve the following problem?

We have a wall with a projection, the projection is divided into grids. The user will hit with a racket a ball that makes impact in one of the projected grids, the system has to detect in which quadrant the ball has made an impact, in order to show another video in the projection.

I can think of different solutions with Arduino but I think they are not optimal, any suggestions?

Thank you!