12. The non-transitory computer-readable storage medium of claim 11 , wherein each identified patch trajectory is associated with one of the semantic regions and comprises a set of the tracked patches for the semantic region.
12. The non-transitory computer-readable storage medium of claim 11 , wherein each identified patch trajectory is associated with one of the semantic regions and comprises a set of the tracked patches for the semantic region. 13. The non-transitory computer-readable storage medium of claim 12 , the actions further comprising representing an identified patch trajectory with a set of associated <r, v, t, 1>tuples representing patches, r representing an identifier of the associated semantic region, v representing an identifier of a video in which the associated semantic region is present, t representing a temporal indicator of a time within the video at which a patch corresponding to the semantic region was identified, and 1 representing a region within a frame of the video in which the semantic region is located at the time.