Rep-Enhancer: Re-parameterizing Neural Network for Real-time Low-light Enhancement in Visual Maritime Surveillance

Vision-based maritime surveillance has become an essential part of the vessel traffic services system. The images collected in low-light maritime conditions often suffer from poor visibility. These images may significantly degenerate the performance of high-level visual tasks and increase the uncertainty in maritime surveillance. To address this problem, we propose a lightweight neural network (Rep-Enhancer) for low-light image enhancement. Specifically, we first design a re-parameterizable multi-branch edge extraction module, i.e., spatial domain-oriented convolution block (SDCB). Furthermore, skip connections and spatial attention operations are employed to strengthen the features. By exploiting these well-strengthened edge features, we can enhance the low-light images effectively with the encoder-decoder structure. The experimental results have shown that Rep-Enhancer can enhance the low-light image qualifiedly while maintaining great inference efficiency.