Hourglass attention for image super-resolution
摘要
SISR is an important research topic in computer vision. Its goal is to reconstruct HR images with rich details from LR inputs. Early methods based on CNNs made some progress, but their performance reached a limit due to limited model capacity and expressiveness. Recently, methods based on Transformers have shown significant improvements in this field. Their ability to capture long-range dependencies makes them well-suited for image reconstruction. However, these models often require high computational resources, which limits their practical use. This paper presents a detailed analysis of SISR and provides one key insight: the reconstruction performance depends on both low-level and high-level features. Then, we propose a novel SR model called HGFormer. This model uses a shallow architecture and introduces a Dynamic Spatial Information Compression (DSIC) module, which reduces computational complexity by converting the spatial information of mid-level features into the channel dimension. This improves both the efficiency and effectiveness of the model. HGFormer is the first method to expand the self-attention window to