X-Prompt: Multi-modal Visual Prompt for Video Object Segmentation
Pinxue Guo, Wanyun Li, Hao Huang, Lingyi Hong, Xinyu Zhou, Zhaoyu Chen, Jinglun Li, Kaixun Jiang, Wei Zhang, Wenqiang Zhang
TL;DR
X-Prompt introduces a universal RGB+X framework for multi-modal video object segmentation by treating the auxiliary modality as a visual prompt to a pretrained RGB VOS foundation model. It comprises the Multi-modal Visual Prompter (MVP), which generates cross-modal prompts, and Multi-modal Adaptation Experts (MAEs), which inject modality-specific knowledge via low-rank adapters while keeping the foundation model frozen. Trained first on RGB data and then adapted to RGB-T, RGB-D, and RGB-E with limited data, X-Prompt achieves state-of-the-art results across 3 tasks and 4 benchmarks, demonstrating strong generalization and reduced task-specific design costs. The approach offers practical impact by enabling robust multi-modal segmentation with lower hardware and data requirements, and the authors release code for reproducibility, highlighting the framework's potential for broad adoption in video understanding applications.
Abstract
Multi-modal Video Object Segmentation (VOS), including RGB-Thermal, RGB-Depth, and RGB-Event, has garnered attention due to its capability to address challenging scenarios where traditional VOS methods struggle, such as extreme illumination, rapid motion, and background distraction. Existing approaches often involve designing specific additional branches and performing full-parameter fine-tuning for fusion in each task. However, this paradigm not only duplicates research efforts and hardware costs but also risks model collapse with the limited multi-modal annotated data. In this paper, we propose a universal framework named X-Prompt for all multi-modal video object segmentation tasks, designated as RGB+X. The X-Prompt framework first pre-trains a video object segmentation foundation model using RGB data, and then utilize the additional modality of the prompt to adapt it to downstream multi-modal tasks with limited data. Within the X-Prompt framework, we introduce the Multi-modal Visual Prompter (MVP), which allows prompting foundation model with the various modalities to segment objects precisely. We further propose the Multi-modal Adaptation Experts (MAEs) to adapt the foundation model with pluggable modality-specific knowledge without compromising the generalization capacity. To evaluate the effectiveness of the X-Prompt framework, we conduct extensive experiments on 3 tasks across 4 benchmarks. The proposed universal X-Prompt framework consistently outperforms the full fine-tuning paradigm and achieves state-of-the-art performance. Code: https://github.com/PinxueGuo/X-Prompt.git
