Text-based Localization of Moments in a Video Corpus
This addresses the challenge of text-based video moment localization across multiple videos, which is incremental as it extends prior work by relaxing the assumption of a known relevant video.
The paper tackles the problem of localizing moments in a corpus of videos for a given sentence query, which involves both retrieving the relevant video and temporally localizing the moment, and demonstrates promising performance on benchmark datasets like Charades-STA, DiDeMo, and ActivityNet Captions.
Prior works on text-based video moment localization focus on temporally grounding the textual query in an untrimmed video. These works assume that the relevant video is already known and attempt to localize the moment on that relevant video only. Different from such works, we relax this assumption and address the task of localizing moments in a corpus of videos for a given sentence query. This task poses a unique challenge as the system is required to perform: (i) retrieval of the relevant video where only a segment of the video corresponds with the queried sentence, and (ii) temporal localization of moment in the relevant video based on sentence query. Towards overcoming this challenge, we propose Hierarchical Moment Alignment Network (HMAN) which learns an effective joint embedding space for moments and sentences. In addition to learning subtle differences between intra-video moments, HMAN focuses on distinguishing inter-video global semantic concepts based on sentence queries. Qualitative and quantitative results on three benchmark text-based video moment retrieval datasets - Charades-STA, DiDeMo, and ActivityNet Captions - demonstrate that our method achieves promising performance on the proposed task of temporal localization of moments in a corpus of videos.