Retrieval-Augmented Egocentric Video Captioning
Authors: Jilan Xu, Yifei Huang, Junlin Hou, Guo Chen, Yuejie Zhang, Rui Feng, Weidi Xie

Understanding human actions from videos of first-person view poses significant challenges. Most prior approaches explore representation learning on egocentric videos only while overlooking the potential benefit of exploiting existing large-scale third-person videos. In this paper (1) we develop EgoInstructor a retrieval-augmented multimodal captioning model that automatically retrieves semantically relevant third-person instructional videos to enhance the video captioning of egocentric videos (2) for training the cross-view retrieval module we devise an automatic pipeline to discover ego-exo video pairs from distinct large-scale egocentric and exocentric datasets (3) we train the cross-view retrieval module with a novel EgoExoNCE loss that pulls egocentric and exocentric video features closer by aligning them to shared text features that describe similar actions (4) through extensive experiments our cross-view retrieval module demonstrates superior performance across seven benchmarks. Regarding egocentric video captioning EgoInstructor exhibits significant improvements by leveraging third-person videos as references.