Structured Video-Language Modeling with Temporal Grouping and Spatial Grounding
This work addresses the need for better fine-grained understanding in video-language models for tasks like temporal localization and semantic reasoning, representing an incremental improvement over existing methods.
The paper tackles the problem of video-language pre-training by addressing the neglect of fine-grained local information in existing methods, proposing S-ViLM with temporal grouping and spatial grounding to improve region-object alignment and temporal-aware features, resulting in substantial performance gains over state-of-the-art methods on four downstream tasks including text-video retrieval and video question answering.
Existing video-language pre-training methods primarily focus on instance-level alignment between video clips and captions via global contrastive learning but neglect rich fine-grained local information in both videos and text, which is of importance to downstream tasks requiring temporal localization and semantic reasoning. A powerful model is expected to be capable of capturing region-object correspondences and recognizing scene changes in a video clip, reflecting spatial and temporal granularity, respectively. To strengthen model's understanding into such fine-grained details, we propose a simple yet effective video-language modeling framework, S-ViLM, by exploiting the intrinsic structures of these two modalities. It includes two novel designs, inter-clip spatial grounding and intra-clip temporal grouping, to promote learning region-object alignment and temporal-aware features, simultaneously. Comprehensive evaluations demonstrate that S-ViLM performs favorably against existing approaches in learning more expressive representations. Specifically, S-ViLM surpasses the state-of-the-art methods substantially on four representative downstream tasks, covering text-video retrieval, video question answering, video action recognition, and temporal action localization.