Variational Optic Flow Computation in Real-Time

Variational methods for optic flow computation have the reputation of producing good results at the expense of being too slow for realtime applications. We show that real-time variational computation of optic flow fields is possible when appropriate methods are combined with modern numerical techniques. We consider the CLG method, a recent variational technique that combines the quality of the dense flow fields of the Horn and Schunck approach with the noise robustness of the Lucas–Kanade method. For the linear system of equations resulting from the discretised Euler–Lagrange equations, we present different multigrid schemes in detail. We show that under realistic accuracy requirements they are up to 247 times more efficient than the widely used Gauß-Seidel algorithm. On a 3.06 GHz PC, we have computed 40 dense flow fields of size 200 × 200 pixels within a single second. AMS 2000 Subject Classification: 68T45, 65N55, 49K20, 65K10, 35J60, 65N04