Multi-Perspective Subimage CLIP with Keyword Guidance for Remote Sensing Image-Text Retrieval
Yifan Li, Shiying Wang, Jianqiang Huang
TL;DR
The paper addresses the mismatch between coarse global alignment in RSITR and the dense, multi-scale semantics of remote sensing imagery, compounded by the high cost of full fine-tuning. It proposes MPS-CLIP, a parameter-efficient framework that uses an LLM to mine keywords guiding SamGeo to generate semantically relevant sub-perspectives, a Gated Global Attention (G^2A) adapter to adapt a frozen CLIP backbone, and a Multi-Perspective Representation (MPR) module to fuse local cues into robust embeddings, optimized with a hybrid objective that combines multi-perspective contrastive and weighted triplet losses. The approach delivers state-of-the-art results on RSICD and RSITMD, significantly outperforming full fine-tuning baselines and recent competitors while maintaining efficiency. These results demonstrate the value of keyword-guided multi-perspective modeling for fine-grained RSITR and suggest potential extensions to other dense prediction tasks in remote sensing.
Abstract
Vision-Language Pre-training (VLP) models like CLIP have significantly advanced Remote Sensing Image-Text Retrieval (RSITR). However, existing methods predominantly rely on coarse-grained global alignment, which often overlooks the dense, multi-scale semantics inherent in overhead imagery. Moreover, adapting these heavy models via full fine-tuning incurs prohibitive computational costs and risks catastrophic forgetting. To address these challenges, we propose MPS-CLIP, a parameter-efficient framework designed to shift the retrieval paradigm from global matching to keyword-guided fine-grained alignment. Specifically, we leverage a Large Language Model (LLM) to extract core semantic keywords, guiding the Segment Anything Model (SamGeo) to generate semantically relevant sub-perspectives. To efficiently adapt the frozen backbone, we introduce a Gated Global Attention (G^2A) adapter, which captures global context and long-range dependencies with minimal overhead. Furthermore, a Multi-Perspective Representation (MPR) module aggregates these local cues into robust multi-perspective embeddings. The framework is optimized via a hybrid objective combining multi-perspective contrastive and weighted triplet losses, which dynamically selects maximum-response perspectives to suppress noise and enforce precise semantic matching. Extensive experiments on the RSICD and RSITMD benchmarks demonstrate that MPS-CLIP achieves state-of-the-art performance with 35.18% and 48.40% mean Recall (mR), respectively, significantly outperforming full fine-tuning baselines and recent competitive methods. Code is available at https://github.com/Lcrucial1f/MPS-CLIP.
