🤖 AI Summary
Existing image geolocation methods rely on synthetic reasoning annotations or external retrieval, which limits their interpretability and generalization. This work proposes Geo-R, a novel end-to-end geolocation framework that eliminates the need for retrieval by introducing a Chain-of-Region hierarchical reasoning architecture. Geo-R leverages a lightweight reinforcement learning approach to automatically discover structured reasoning paths from ground-truth coordinates, guided by a Haversine distance–based coordinate alignment reward. It further integrates vision-language models with rule-driven geographic entity mapping to enhance spatial reasoning. Evaluated across multiple benchmarks, Geo-R achieves substantial improvements in localization accuracy and cross-domain generalization, establishing a new paradigm that is both interpretable and scalable.
📝 Abstract
Recent advances in vision-language models have opened up new possibilities for reasoning-driven image geolocalization. However, existing approaches often rely on synthetic reasoning annotations or external image retrieval, which can limit interpretability and generalizability. In this paper, we present Geo-R, a retrieval-free framework that uncovers structured reasoning paths from existing ground-truth coordinates and optimizes geolocation accuracy via reinforcement learning. We propose the Chain of Region, a rule-based hierarchical reasoning paradigm that generates precise, interpretable supervision by mapping GPS coordinates to geographic entities (e.g., country, province, city) without relying on model-generated or synthetic labels. Building on this, we introduce a lightweight reinforcement learning strategy with coordinate-aligned rewards based on Haversine distance, enabling the model to refine predictions through spatially meaningful feedback. Our approach bridges structured geographic reasoning with direct spatial supervision, yielding improved localization accuracy, stronger generalization, and more transparent inference. Experimental results across multiple benchmarks confirm the effectiveness of Geo-R, establishing a new retrieval-free paradigm for scalable and interpretable image geolocalization. To facilitate further research and ensure reproducibility, both the model and code will be made publicly available.