V-Sparse: From temporal-spatial visual semantic compression to coarse-to-fine interaction for text-video retrieval

Text-to-video retrieval refers to the task of finding the most relevant videos in a large-scale unlabeled video collection based on a given text query. In recent years, CLIP-based text-video retrieval methods have developed rapidly, with research primarily focusing on feature-enhancement techniques and interaction strategies. However, due to the concise nature of text and the rich modalities of video, computing similarity scores alone is insufficient for high-precision cross-modal retrieval. To address the inherent imbalance in cross-modal matching, we propose a novel text-video retrieval model, named V-Sparse, which includes visual semantic compression for feature enhancement and coarse-to-fine alignment for feature interaction. First, we propose a text-guided Visual Semantic Compression (VSC) module, consisting of Temporal (TVSC) frame-level and Spatial (SVSC) patch-level compression, aimed at reducing feature redundancy and providing precision support for coarse-to-fine interaction. Second, benefiting from visual semantic compression, we propose a novel Coarse-to-Fine granularity Interaction module (CFI), which aligns sentences with frames, sentences with patches, and words with patches from a unified joint feature encoding perspective. VSC and CFI jointly facilitate cross-modal text-video alignment from the perspectives of feature enhancement and feature interaction, greatly mitigating the inherent imbalance in modal pairing. We evaluate the performance of V-Sparse on six benchmark datasets and achieve state-of-the-art results in both long-video and short-text retrieval. Importantly, V-Sparse demonstrates the importance of feature compression in cross-modal interaction through extensive ablations and offers an effective intermediate pathway for modality interaction. Code will be available at https://github.com/OPA067/V-Sparse.