Estimating the spin of a table tennis ball using Inverse Compositional Image Alignment

In this paper, we propose a method for estimating the rotational velocity of a table tennis ball with Inverse Compositional Image Alignment, ICIA. Assuming orthogonal projection of the camera, we derive an update rule for the motion parameters. Because of the precomputation of the Hessian matrix in ICIA and the simplifying assumptions, the motion parameters estimation at each frame is very fast. We evaluate results for measuring the spins in a synthesized sequence, as well as in real image sequences of table tennis rallies.