Abstract
We present an optical flow estimation approach that operates on the full four-dimensional cost volume. This direct
approach shares the structural benefits of leading stereo
matching pipelines, which are known to yield high accuracy. To this day, such approaches have been considered
impractical due to the size of the cost volume. We show that
the full four-dimensional cost volume can be constructed in
a fraction of a second due to its regularity. We then exploit
this regularity further by adapting semi-global matching to
the four-dimensional setting. This yields a pipeline that
achieves significantly higher accuracy than state-of-the-art
optical flow methods while being faster than most. Our approach outperforms all published general-purpose optical
flow methods on both Sintel and KITTI 2015 benchmarks