Self-supervised learning on a lightweight low-light image enhancement model with curve refinement

Deep learning networks with deeper layers become a trend for their good performance, but lacks the potential for real-time mobile deployment. Another challenge for paired training networks is the limited generalization capacity caused by the sample bias. To overcome these two challenges, we propose a lightweight self-supervised low-light image enhancement method, that trains with low light images only. Specifically, our method consists of a low-resolution dense CNN network stream and a full-resolution guidance stream, responsible for image-to-curve transformation with refinement and spatial guidance fusion, respectively. Then, a new self-supervised loss function is introduced to measure the restored patch-based color deviations among color channels. Experimental results show that our method gives competitive performance to the full-supervised approaches.