SPH-Net: Hyperspectral Image Super-Resolution via Smoothed Particle Hydrodynamics Modeling

Reconstructing a high-resolution hyperspectral image (HSI) from a low-resolution HSI is significant for many applications, such as remote sensing and aerospace. Most deep learning-based HSI super-resolution methods pay more attention to developing novel network structures but rarely study the HSI super-resolution problem from the perspective of image dynamic evolution. In this article, we propose that the HSI pixel motion during the super-resolution reconstruction process can be analogized to the particle movement in the smoothed particle hydrodynamics (SPH) field. To this end, we design an SPH network (SPH-Net) for HSI super-resolution in light of the SPH theory. Specifically, we construct a smooth function based on SPH and design a smooth convolution in multiscales to exploit spectral correlation and preserve the spectral information in the super-resolved image. In addition, we apply the SPH approximation method to discretize the Navier–Stokes motion equation into SPH equation form, which can guide the HSI pixel motion in the desired direction during super-resolution reconstruction, thereby producing clear edges in the spatial domain. Experiments on three public hyperspectral datasets demonstrate that the proposed SPH-Net outperforms the state-of-the-art methods in terms of objective metrics and visual quality.