Diffusion Models Based Null-Space Learning for Remote Sensing Image Dehazing

Remote sensing (RS) dehazing is a challenge topic, as images captured under hazy scenarios often suffer from seriously quality degradation and inconsistency. RS image restoration has been significantly improved with the use of learning-based ways, while current methods are still struggling to restore the complex details for large irregular RS images with ununiform haze. In this letter, we propose an adaptive diffusion null-space dehazing network (ADND-Net), which is a novel diffusion-model-based null-space (NULL) learning toward free-form RS image dehazing. Specifically, a range-null-space decomposition is applied to improve the reverse diffusion process for image consistence. With the help of range-null-space content, we further advance the adaptive region-based diffusion (RD) module to address the unlimited-size RS images and increase the dehazed image quality. Extensive experiments show that our designed model outperforms other comparing dehazing methods on both synthetic and real-world RS datasets.