# Best way to calculate speed of a Bowling Ball

I am working on detecting Bowling Lane and Ball on it and my final objective is to calculate speed of the ball between two fixed points (see two yellow lines). The phone is mounted on a fixed tripod. I am looking for input on how to implement this. I am working with OpenCV3, Android and NDK (native C++).

I think I need two things done correctly to get good results:

mapping of lane (I need to detect first two edges and angle, then I can calculate the length because I know the real-life measurements of the lane). If this step is done correctly, I can (mathematically) reconstruct a top-down view.

ball detection

With these two steps I know how much time have passed before the ball gets from first yellow line to the second hence I can calculate the speed. I do not need to do this in real-time therefore I can save all the frames and do all the heavy calculations after the ball gets off the lane.

Does this sound reasonable and feasible?

Some possible hints:

I would suggest you to place the camera at a fixed location where you will not see the players at all.

Related question: Tracking a bowling ball down the lane.

Thanks Eduardo, this will help a lot! Others are still encouraged to comment on this.