Topic Suggestion: Optical Flow

I think a really interesting topic to cover would be Optical Flow. Not only does it look really cool from the code library examples that I've found when the vector movement is drawn from movement in the video, but I haven't seen a good introduction done on the topic. From what I've seen while looking around for an introduction to the themes and topics of how Optical Flow works, it would be nice to get a better understanding of how the existing libraries function. At the moment I've only come across the libraries available in Processing which can be a little tricky to figure out or there are academic papers on the subject. Nothing really in the middle, say as in an introduction or fundamentals to the topic to help creatively expand on or make better use of the existing libraries.

Thanks!