Towards Lightweight Hyperspectral Image Super-Resolution with Depthwise Separable Dilated Convolutional Network
Usman Muhammad, Jorma Laaksonen, Lyudmila Mihaylova
TL;DR
This work tackles hyperspectral image super-resolution by introducing a lightweight depthwise separable dilated convolutional network (DSDCN) inspired by MobileNet, augmented with a dilated fusion block to capture multi-scale spatial-spectral features. A band-grouping strategy reduces spectral redundancy, while a tri-component loss combining $L_{MSE}$, $L_{SAM}$, and $L_{ ext{L2}}$ guides high-fidelity reconstruction. Empirical results on the PaviaC and PaviaU datasets show that DSDCN achieves competitive PSNR, MSSIM, and SAM scores with only ~0.96M parameters, outperforming several larger models on PaviaC and remaining highly competitive on PaviaU. Overall, the method offers a practical, resource-efficient solution for hyperspectral SR suitable for real-world applications.
Abstract
Deep neural networks have demonstrated highly competitive performance in super-resolution (SR) for natural images by learning mappings from low-resolution (LR) to high-resolution (HR) images. However, hyperspectral super-resolution remains an ill-posed problem due to the high spectral dimensionality of the data and the scarcity of available training samples. Moreover, existing methods often rely on large models with a high number of parameters or require the fusion with panchromatic or RGB images, both of which are often impractical in real-world scenarios. Inspired by the MobileNet architecture, we introduce a lightweight depthwise separable dilated convolutional network (DSDCN) to address the aforementioned challenges. Specifically, our model leverages multiple depthwise separable convolutions, similar to the MobileNet architecture, and further incorporates a dilated convolution fusion block to make the model more flexible for the extraction of both spatial and spectral features. In addition, we propose a custom loss function that combines mean squared error (MSE), an L2 norm regularization-based constraint, and a spectral angle-based loss, ensuring the preservation of both spectral and spatial details. The proposed model achieves very competitive performance on two publicly available hyperspectral datasets, making it well-suited for hyperspectral image super-resolution tasks. The source codes are publicly available at: \href{https://github.com/Usman1021/lightweight}{https://github.com/Usman1021/lightweight}.
