Cross-modal Representation Shift Refinement for Point-supervised Video Moment Retrieval

Video Moment Retrieval (VMR) aims to retrieve temporal moments in videos that align with natural language queries, a task requiring cross-modal reasoning between video and text. Among various supervision paradigms, point-supervised VMR has emerged as a practical solution, leveraging single-frame annotations to significantly reduce annotation costs while maintaining competitive retrieval performance. However, this sparse supervision approach induces cross-modal representation shift. This shift complicates the model’s ability to accurately capture action sequences and associate text with visual content. To tackle this, we propose a novel framework called pseuDo fRame-based tempOral and semaNtic rEfinement (DRONE) with two key modules: (1) Pseudo-Frame Temporal Alignment (PTA), which embeds textual queries as pseudo-frames to enhance temporal coherence, and (2) Curriculum-Guided Semantic Refinement (CSR), which uses a progressive contrastive learning strategy to refine semantic representations from easy to hard cases. Extensive experiments show that DRONE achieves effective retrieval performance while keeping annotation costs low.