Multi-scale strip-shaped convolution attention network for lightweight image super-resolution

Lightweight convolutional neural networks for Single Image Super-Resolution (SISR) have exhibited remarkable performance improvements in recent years. These models achieve excellent performance by relying on attention mechanisms that incorporate square-shaped convolutions to enhance feature representation. However, these approaches still suffer from redundancy which comes from square-shaped convolutional kernels and overlooks the utilization of multi-scale information. In this paper, we propose a novel attention mechanism called Multi-scale Strip-shaped convolution Attention (MSA), which utilizes three sets of differently sized depth-wise separable stripe convolution kernels in parallel to replace the redundant square-shaped convolution attention and extract multi-scale features. We also generalize MSA to other lightweight neural network models, and experimental results show that MSA outperforms other convolutional based attention mechanisms. Building upon MSA, we propose an Efficient Feature Extraction Block (EFEB), a lightweight block for SISR. Finally, based on EFEB, we propose a lightweight image super-resolution neural network named Multi-scale Strip-shaped convolution Attention Network (MSAN). Experiments demonstrate that MSAN outperforms existing state-of-the-art lightweight SR methods with fewer parameters and lower computational complexity.