Degradation-Noise-Aware Deep Unfolding Transformer for Hyperspectral Image Denoising

Abstract

Hyperspectral images (HSIs) play a pivotal role in fields, such as medical diagnosis and agriculture. However, it often contends with significant noise stemming from narrowband spectral filtering. Existing denoising techniques have their limitations: model-driven methods rely on manual priors and hyperparameters, while learning-based methods struggle to discern intrinsic noise patterns, as they require paired images with specific example noise for training, fail to capture critical noise distribution information, leading to unrobust denoising results. This work addresses the issue by presenting a degradation-noise-aware unfolding network (DNA-Net). Unlike training directly with the simulated noise, DNA-Net initially models general sparse and Gaussian noise through statistic distributions. It then explicitly represents image priors with a customized spectral transformer. The model is subsequently unfolded into an end-to-end (E2E) network, with hyperparameters adaptively estimated from noisy HSI and degradation models, effectively regulating each iteration. Furthermore, a novel U-shaped local-nonlocal–spectral transformer (U-LNSA) is introduced, simultaneously capturing spectral correlations, local features, and nonlocal dependencies. The integration of U-LNSA into DNA-Net establishes the first Transformer-based deep unfolding method for HSI denoising. Experimental results on synthetic and real noise validate DNA-Net’s superior performance over state-of-the-art (SOTA) methods. Moreover, the DNA-Net, trained exclusively on mixed Gaussian noise and impulse noise, demonstrates the ability to generalize to unseen noise present in real images. Code and models will be released at: https://github.com/NavyZeng/DNA-Net.