GeoJapan Fusion Framework: A Large Multimodal Model for Regional Remote Sensing Recognition

Recent advances in large multimodal models (LMMs) have opened new opportunities for multitask recognition from remote sensing images. However, existing approaches still face challenges in effectively recognizing the complex geospatial characteristics of regions such as Japan, where its location along the seismic belt leads to highly diverse urban environments and cityscapes that differ from those in other regions. To overcome these challenges, we propose the GeoJapan Fusion Framework (GFF), a multimodal architecture that integrates a large language model (LLM) and a vision–language model (VLM) and strengthens multimodal alignment ability through an in-context learning mechanism to support multitask recognition for Japanese remote sensing images. The GFF also incorporates a cross-modal feature fusion mechanism with low-rank adaptation (LoRA) to enhance representation alignment and enable efficient model adaptation. To facilitate the construction of the GFF, we construct the GeoJapan dataset, which comprises a substantial collection of high-quality Japanese remote sensing images, designed to facilitate multitask recognition using LMMs. We conducted extensive experiments and compared our method with state-of-the-art LMMs. The experimental results demonstrate that GFF outperforms previous approaches across multiple tasks, demonstrating its promising ability for multimodal multitask remote sensing recognition.