Rethinking Cross-Modal Interaction for Efficient Referring Image Segmentation

Referring Image Segmentation, the task of finding and segmenting objects in an image conditioned on a natural language description, is crucial for human-robot collaboration. However, current RIS methods often implement visual-text alignment relying on computationally intensive Transformer-based self-attention mechanisms, which impairs deployment on robots, especially those with limited computational resources. Indeed, beyond accuracy, practical robotic applications demand efficient models with small footprints. This letter introduces ERIS, an Efficient RIS approach designed for real-world deployment. ERIS achieves effective multi-modal interaction through a novel dual-branch architecture: a Visual Text Alignment branch and a Text Visual Refinement branch. This design implements bilateral alignment between textual and visual modalities without the computational burden of self-attention. Of note, the progressive alignment in ERIS enhances interpretability, revealing how textual cues guide segmentation. For the sake of efficiency, our alignment strategy produces structured embeddings which can be directly mapped into the final segmentation mask, without the need for additional segmentation heads. Thus, ERIS footprint scales linearly with respect to the number of visual and text tokens, making it suitable for both cloud-based and edge deployment. Experimental results demonstrate that ERIS achieves competitive or superior performance compared to state-of-the-art methods while significantly reducing computational cost, proving that efficiency and accuracy are not mutually exclusive.