SAR Despeckling via Regional Denoising Diffusion Probabilistic Model
Xuran Hu, Ziqiang Xu, Zhihan Chen, Zhengpeng Feng, Mingzhe Zhu, LJubisa Stankovic
TL;DR
Speckle noise in SAR images complicates despeckling, especially for large-scale imagery. The authors propose Region Denoising Diffusion Probabilistic Model (R-DDPM), which trains a diffusion process on image regions and employs region-guided inverse sampling to deliver high-quality despeckling across arbitrary scales. Key innovations include regional diffusion for scale flexibility, a lightweight network with DDIM-inspired acceleration, and overlapping-region sampling to prevent edge artifacts. Experiments on Sentinel-1 data show that R-DDPM outperforms state-of-the-art methods in PSNR/SSIM and real-image metrics (ENL, EPI), with low GPU memory footprint and straightforward deployment.
Abstract
Speckle noise poses a significant challenge in maintaining the quality of synthetic aperture radar (SAR) images, so SAR despeckling techniques have drawn increasing attention. Despite the tremendous advancements of deep learning in fixed-scale SAR image despeckling, these methods still struggle to deal with large-scale SAR images. To address this problem, this paper introduces a novel despeckling approach termed Region Denoising Diffusion Probabilistic Model (R-DDPM) based on generative models. R-DDPM enables versatile despeckling of SAR images across various scales, accomplished within a single training session. Moreover, The artifacts in the fused SAR images can be avoided effectively with the utilization of region-guided inverse sampling. Experiments of our proposed R-DDPM on Sentinel-1 data demonstrates superior performance to existing methods.
