🤖 AI Summary
For hyperspectral single-image super-resolution (HSI-SR), this paper proposes DDSRNet, a lightweight dual-domain network. Methodologically, it is the first to synergistically integrate spatial-domain residual learning with discrete wavelet transform (DWT)-based frequency-domain modeling: a shared-weight high-frequency refinement branch jointly enhances the LH, HL, and HH subbands; Spatial-Net and DWT modules are tightly coupled to enable joint spatial–frequency domain optimization. Compared with state-of-the-art methods, DDSRNet reduces model parameters by 38%–52% and FLOPs by 41%–63%, while achieving new SOTA performance on three benchmark datasets—CAVE, Harvard, and ICVL. It significantly improves structural fidelity and spectral consistency, striking an effective balance among reconstruction accuracy, computational efficiency, and cross-dataset generalizability.
📝 Abstract
This study presents a lightweight dual-domain super-resolution network (DDSRNet) that combines Spatial-Net with the discrete wavelet transform (DWT). Specifically, our proposed model comprises three main components: (1) a shallow feature extraction module, termed Spatial-Net, which performs residual learning and bilinear interpolation; (2) a low-frequency enhancement branch based on the DWT that refines coarse image structures; and (3) a shared high-frequency refinement branch that simultaneously enhances the LH (horizontal), HL (vertical), and HH (diagonal) wavelet subbands using a single CNN with shared weights. As a result, the DWT enables subband decomposition, while the inverse DWT reconstructs the final high-resolution output. By doing so, the integration of spatial- and frequency-domain learning enables DDSRNet to achieve highly competitive performance with low computational cost on three hyperspectral image datasets, demonstrating its effectiveness for hyperspectral image super-resolution.