DRCNet: Dynamic Image Restoration Contrastive Network

Fei Li, Lingfeng Shen, Yang Mi, Zhenbo Li ;

"Image restoration aims to recover images from spatially-varying degradation. Most existing image-restoration models employed static CNN-based models, where the fixed learned filters cannot fit the diverse degradation well. To address this, in this paper, we propose a novel Dynamic Image Restoration Contrastive Network (DRCNet). The principal block in DRCNet is theDynamic Filter Restoration module (DFR), which mainly consists of the spatial filter branch and the energy-based attention branch. Specifically, the spatial filter branch suppresses spatial noise for varying spatial degradation; the energy-based attention branch guides the feature integration for better spatial detail recovery. To make degraded images and clean images more distinctive in the representation space, we develop a novel Intra-class Contrastive Regularization (Intra-CR) to serve as a constraint in the solution space for DRCNet. Meanwhile, our theoretical derivation proved Intra-CR owns less sensitivity towards hyper-parameter selection than previous contrastive regularization. DRCNet achieves state-of-the-art results on the ten widely-used benchmarks in image restoration. Besides, we conduct ablation studies to show the effectiveness of the DFR module and Intra-CR, respectively."