Attention feature matching for weakly-supervised video relocalization.

Localizing the desired video clip for a given query in an untrimmed video has been a hot research topic for multimedia understanding. Recently, a new task named video relocalization, in which the query is a video clip, has been raised. Some methods have been developed for this task, however, these methods often require dense annotations of the temporal boundaries inside long videos for training. A more practical solution is the weakly-supervised approach, which only needs the matching information between the query and video. Motivated by that, we propose a weakly-supervised video relocalization approach based on an attention-based feature matching method. Specifically, it recognizes the video clip by finding the clip whose frames are the most relevant to the query clip frames based on the matching results of the frame embeddings. In addition, an attention module is introduced to identify the frames containing rich semantic correlations in the query video. Extensive experiments on the ActivityNet dataset demonstrate that our method can outperform several weakly-supervised methods consistently and even achieve competing performance to supervised baselines.