Lightweight frequency-spatial distillation attention network for image super-resolution
摘要
Lightweight image super-resolution (SR) methods prioritize computational efficiency but often rely on restricted receptive fields or shallow architectures, making it difficult to recover complex textures and long-range structures. Furthermore, conventional attention mechanisms are typically confined to spatial or channel domains, underutilizing frequency information and leading to significant high-frequency detail loss. To address these limitations, we propose the Lightweight Frequency-Spatial Distillation Attention Network (FSDAN), aimed at coordinating global structural consistency and local high-frequency textures under strict parameter constraints. Specifically, we construct the Frequency-Spatial Interaction Unit (FSIU), which employs Fast Fourier Convolution (FFC) to capture global frequency structures and multi-scale Blueprint Separable Convolutions (BSConv) to extract hierarchical spatial textures. This dual-branch mechanism effectively enhances both long-range contextual and local detail representations. Building upon this, the Progressive Frequency-Spatial Fusion Block (PFSFB) facilitates layer-by-layer feature enhancement-from local textures to global structures-through multi-level distillation and phased fusion. Additionally, the Frequency-Domain Guided Attention Enhancement Module (FGAEM) utilizes global frequency priors to dynamically regulate multi-scale spatial attention, fostering robust cross-scale interaction and texture refinement. Extensive experiments demonstrate that FSDAN achieves highly competitive performance against state-of-the-art lightweight models, offering a favorable trade-off among complexity, reconstruction quality, and inference speed. The code and pre-trained models are available at https://github.com/Anytime23/FSDAN.