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.