Information-Growth Attention Network for Image Super-Resolution

It is generally known that a high-resolution (HR) image contains more productive information compared with its low-resolution (LR) versions, so image super-resolution (SR) satisfies an information-growth process. Considering the property, we attempt to exploit the growing information via a particular attention mechanism. In this paper, we propose a concise but effective Information-Growth Attention Network (IGAN) that shows the incremental information is beneficial for SR. Specifically, a novel information-growth attention is proposed. It aims to pay attention to features involving large information-growth capacity by assimilating the difference from current features to the former features within a network. We also illustrate its effectiveness contrasted by widely-used self-attention using entropy and generalization analysis. Furthermore, existing channel-wise attention generation modules (CAGMs) have large informational attenuation due to directly calculating global mean for feature maps. Therefore, we present an innovative CAGM that progressively decreases feature maps' sizes, leading to more adequate feature exploitation. Extensive experiments also demonstrate IGAN outperforms state-of-the-art attention-aware SR approaches.