URDM: Hyperspectral Unmixing Regularized by Diffusion Models

Hyperspectral unmixing aims to decompose the mixed pixels into pure spectra and calculate their corresponding fractional abundances. It holds a critical position in hyperspectral image processing. Traditional model-based unmixing methods use convex optimization to iteratively solve the unmixing problem with hand-crafted regularizers. While their performance is limited by these manually designed constraints, which may not fully capture the structural information of the data. Recently, deep learning-based unmixing methods have shown remarkable capability for this task. However, they have limited generalizability and lack interpretability. In this paper, we propose a novel hyperspectral unmixing method regularized by a diffusion model (URDM) to overcome these shortcomings. Our method leverages the advantages of both conventional optimization algorithms and deep generative models. Specifically, we formulate the unmixing objective function from a variational perspective and integrate it into a diffusion sampling process to introduce generative priors from a denoising diffusion probabilistic model (DDPM). Since the original objective function is challenging to optimize, we introduce a splitting-based strategy to decouple it into simpler subproblems. Extensive experiment results conducted on both synthetic and real datasets demonstrate the efficiency and superior performance of our proposed method.