Comment by masom

I remember NodeCopter and running OpenCV to control them years ago.

https://gist.github.com/andrew/2f81952f4867d1b200bb

The big difference is they can now run this on the copter instead of being remotely controlled; a 100$ raspberry pi has enough processing power for this, and so does several other off-the-shelf mini computers powered by lithium batteries.

Crazy times.