Just Functioning as a Hook for Two-Stage Referring Multi-Object Tracking

Abstract: Referring Multi-Object Tracking (RMOT) aims to localize target trajectories specified by natural language expressions in videos. Existing RMOT methods mainly follow two paradigms: one-stage strategies and two-stage ones. The former jointly trains tracking with referring but suffers from substantial computational overhead. Although the latter improves efficiency, it overlooks the inherent contextual aggregation capabilities of pre-trained visual backbones and takes a detour. Meanwhile, its fixed dual-tower architecture restricts compatibility with other visual / text backbones. To address these limitations, we propose JustHook, a novel hook-like framework for two-stage RMOT, which introduces two core components: (1) a Visual Feature Hook (VFH), enabling JustHook to extract context-rich local features directly from the original visual backbone like a hook; (2) a Parallel Combined Decoder (PCD), which transforms the passive cosine similarity measurement between independent modalities into active contrastive learning within the combined feature space. The proposed JustHook not only leverages the capabilities of pre-trained models but also breaks free from the constraints of inherent modality alignment, achieving strong scalability. Extensive experiments on Refer-KITTI and Refer-KITTI-V2 demonstrate that JustHook outperforms state-of-the-art methods across diverse encoder combinations, achieving a notable 7.77\% HOTA improvement on Refer-KITTI-V2. Code will be made available soon.