Semantic guided large scale factor remote sensing image super-resolution with generative diffusion prior

In the realm of remote sensing, images captured by different platforms exhibit significant disparities in spatial resolution. Consequently, effective large scale factor super-resolution (SR) algorithms are vital for maximizing the utilization of low-resolution (LR) satellite data captured from orbit. However, existing methods confront challenges such as semantic inaccuracies and blurry textures in the reconstructed images. To tackle these issues, we introduce a novel framework, the Semantic Guided Diffusion Model (SGDM), designed for large scale factor remote sensing image super-resolution. The framework exploits a pre-trained generative model as a prior to generate perceptually plausible high-resolution (HR) images, thereby constraining the solution space and mitigating texture blurriness. We further enhance the reconstruction by incorporating vector maps, which carry structural and semantic cues to enhance the reconstruction fidelity of ground objects. Moreover, pixel-level inconsistencies in paired remote sensing images, stemming from sensor-specific imaging characteristics, may hinder the convergence of the model and the diversity in generated results. To address this problem, we develop a method to extract sensor-specific imaging characteristics and model the distribution of them. The proposed model can decouple imaging characteristics from image content, allowing it to generate diverse super-resolution images based on imaging characteristics provided by reference satellite images or sampled from the imaging characteristic probability distributions. To validate and evaluate our approach, we create the Cross-Modal Super-Resolution Dataset (CMSRD). Qualitative and quantitative experiments on CMSRD showcase the superiority and broad applicability of our method. Experimental results on downstream vision tasks also demonstrate the utilitarian of the generated SR images. The dataset and code will be publicly available at https://github.com/wwangcece/SGDM.