RT-RMOT: A Dataset and Framework for RGB-Thermal Referring Multi-Object Tracking

RGB-Thermal (RGBT) tracking aims to achieve robust object localization across diverse environmental conditions by fusing visible and thermal infrared modalities. However, existing RGBT trackers rely solely on initial-frame visual information for target modeling, failing to adapt to appearance variations due to the absence of language guidance. Furthermore, current methods suffer from redundant search regions and heterogeneous modality gaps, causing background distraction. To address these issues, we first introduce textual descriptions into RGBT tracking benchmarks. This is accomplished through a pipeline that leverages Multi-modal Large Language Models (MLLMs) to automatically produce texual annotations. Afterwards, we propose RAGTrack, a novel Retrieval-Augmented Generation framework for robust RGBT tracking. To this end, we introduce a Multi-modal Transformer Encoder (MTE) for unified visual-language modeling. Then, we design an Adaptive Token Fusion (ATF) to select target-relevant tokens and perform channel exchanges based on cross-modal correlations, mitigating search redundancies and modality gaps. Finally, we propose a Context-aware Reasoning Module (CRM) to maintain a dynamic knowledge base and employ a Retrieval-Augmented Generation (RAG) to enable temporal linguistic reasoning for robust target modeling. Extensive experiments on four RGBT benchmarks demonstrate that our framework achieves state-of-the-art performance across various challenging scenarios. The source code is available https://github.com/IdolLab/RAGTrack.

Referring Multi-Object Tracking (RMOT) aims to track specific targets based on language descriptions, playing a vital role in interactive AI systems such as robotics and autonomous driving. However, existing RMOT methods rely exclusively on 2D RGB observations. Since similar 2D projections can correspond to different 3D configurations, the available observations may not uniquely determine the referred targets. This creates a fundamental mismatch between the task requirements and the available input. To advance research on the DRMOT task, we construct DRSet, a dataset tailored for the DRMOT task. DRSet comprises 2,076 referring expressions over 186 RGB-D source sequences. It features synchronized RGB images and depth maps paired with language descriptions, including explicit depth-dependent descriptions, to systematically evaluate spatial-semantic detection and tracking capabilities. Furthermore, we propose DRTrack, an MLLM-guided depth-referring tracking framework. DRTrack leverages a Geometric-Aware GRPO fine-tuned Multimodal Large Language Model (MLLM) to achieve precise spatial-semantic detection from joint L+RGB+D inputs, while incorporating explicit depth cues to enforce robust trajectory association. Extensive experiments on the DRSet dataset demonstrate the effectiveness of our framework. Our dataset and code will be available at https://github.com/chen-si-jia/DRMOT.

Referring multi-object tracking (RMOT) is a task of associating all the objects in a video that semantically match with given textual queries or referring expressions. Existing RMOT approaches decompose object grounding and tracking into separated modules and exhibit limited performance due to the scarcity of training videos, ambiguous annotations, and restricted domains. In this work, we introduce STORM, an end-to-end MLLM that jointly performs grounding and tracking within a unified framework, eliminating external detectors and enabling coherent reasoning over appearance, motion, and language. To improve data efficiency, we propose a task-composition learning (TCL) strategy that decomposes RMOT into image grounding and object tracking, allowing STORM to leverage data-rich sub-tasks and learn structured spatial--temporal reasoning. We further construct STORM-Bench, a new RMOT dataset with accurate trajectories and diverse, unambiguous referring expressions generated through a bottom-up annotation pipeline. Extensive experiments show that STORM achieves state-of-the-art performance on image grounding, single-object tracking, and RMOT benchmarks, demonstrating strong generalization and robust spatial--temporal grounding in complex real-world scenarios. STORM-Bench is released at https://github.com/amazon-science/storm-referring-multi-object-grounding.