Motion Estimation

Why estimate motion?

Optical flow

Problem definition:  optical flow

Optical flow constraints (grayscale images)

Optical flow equation

Optical flow equation

Aperture problem

Aperture problem

Solving the aperture problem

Lucas-Kanade flow

Conditions for solvability

Errors in Lucas-Kanade

Improving accuracy

Iterative Refinement

Revisiting the small motion assumption

Reduce the resolution!

Coarse-to-fine optical flow estimation

Coarse-to-fine optical flow estimation

Optical flow result

Motion tracking

Tracking features

Application:  Rotoscoping (demo)