US Patent 9418297 Detecting video copies

A computer-implemented method for detecting a copy of a reference video, comprises segmenting respective ones of multiple frames of the reference video into multiple regions, determining sets of image features appearing in respective ones of the multiple frames, determining a measure for the relative number of image features for a given region across the multiple frames, generating a spatio-temporal signature for the reference video using the determined measures, and comparing the signature for the reference video against a spatio-temporal signature of a query video to determine a likelihood of a match.