The remarkable achievements of ChatGPT and Generative Pre-trained Transformer 4 (GPT-4) have sparked a wave of interest and research in the field of large language models (LLMs) for artificial general intelligence (AGI). These models provide intelligent solutions that are closer to human thinking, enabling us to use general artificial intelligence (AI) to solve problems in various applications. However, in the field of remote sensing (RS), the scientific literature on the implementation of AGI remains relatively scant. Existing AI-related research in RS focuses primarily on visual-understanding tasks while neglecting the semantic understanding of the objects and their relationships. This is where vision-LMs (VLMs) excel as they enable reasoning about images and their associated textual descriptions, allowing for a deeper understanding of the underlying semantics. VLMs can go beyond visual recognition of RS images and can model semantic relationships as well as generate natural language descriptions of the image. This makes them better suited for tasks that require both visual and textual understanding, such as image captioning and visual question answering (VQA). This article provides a comprehensive review of the research on VLMs in RS, summarizing the latest progress, highlighting current challenges, and identifying potential research opportunities. Specifically, we review the application of VLMs in mainstream RS tasks, including image captioning, text-based image generation, text-based image retrieval (TBIR), VQA, scene classification, semantic segmentation, and object detection. For each task, we analyze representative works and discuss research progress. Finally, we summarize the limitations of existing works and provide possible directions for future development. This review aims to provide a comprehensive overview of the current research progress of VLMs in RS (see Figure 1), and to inspire further research in this exciting and promising field.

In this article, we deal with the problem of object detection on remote sensing images. Previous researchers have developed numerous deep convolutional neural network (CNN)-based methods for object detection on remote sensing images, and they have reported remarkable achievements in detection performance and efficiency. However, current CNN-based methods often require a large number of annotated samples to train deep neural networks and tend to have limited generalization abilities for unseen object categories. In this article, we introduce a metalearning-based method for few-shot object detection on remote sensing images where only a few annotated samples are needed for the unseen object categories. More specifically, our model contains three main components: a metafeature extractor that learns to extract metafeature maps from input images, a feature reweighting module that learns class-specific reweighting vectors from the support images and use them to recalibrate the metafeature maps, and a bounding box prediction module that carries out object detection on the reweighted feature maps. We build our few-shot object detection model upon the YOLOv3 architecture and develop a multiscale object detection framework. Experiments on two benchmark data sets demonstrate that with only a few annotated samples, our model can still achieve a satisfying detection performance on remote sensing images, and the performance of our model is significantly better than the well-established baseline models.