Hyperspectral image super-resolution using spatial-spectral attention and spectral transformer
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Abstract
Hyperspectral image super-resolution (HSI-SR) aims to reconstruct high-resolution hyperspectral images (HR-HSI) from low-resolution observations (LR-HSI). Existing convolutional neural network (CNN)-based methods excel at extracting local spatial features but struggle to capture long-range spectral dependencies, while full spatial Transformer architectures incur high computational cost. We propose ESSA-SSAM-SpecTrans, a hybrid architecture that extends the Efficient Spectral-Spatial Attention (ESSA) baseline with two novel modules: (1) a Separated Spatial-Spectral Attention Module (SSAM) that independently models spatial and spectral features in 2D image space via dual-branch attention, and (2) a Spectral Transformer that applies multi-head self-attention along the spectral dimension, treating each spectral band as a token with complexity O(C2·HW) instead of O((HW)2·C). Experiments on two benchmark datasets with a scale factor of ×4 demonstrate the effectiveness of the proposed approach. On the CAVE dataset, the model achieves a PSNR of 37.78 dB, an SSIM of 0.960, and an ERGAS of 3.18, the best results among the compared methods on these three metrics. On the Pavia Centre dataset, it achieves the lowest SAM (4.80°) and ERGAS (5.51), indicating strong spectral fidelity on real-world remote-sensing data.
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© 2026 The authors. This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License.
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