ULBPNet: Low-light image enhancement using U-shaped lightening back-projection

Images captured under low-light conditions often have various issues, such as low brightness and contrast, and also color distortion. The aim of low-light image enhancement is to improve the visual quality of such images to facilitate subsequent image processing and computer vision tasks. However, this task faces major challenges from the inherent limitations of the low-light environment. This paper proposes a novel low-light image enhancement network using a U-shaped enhanced lightening back-projection. The network architecture primarily comprises a series of lightening blocks and a color balance block. We construct the lightening block, which incorporates a U-shaped enhanced lightening back-projection module and a saturation-guided fusion module, by assuming that the saturation levels of the low-light and the normal images are similar. Additionally, a color balance block is included to address issues such as color fading or over-enhancement. The effectiveness of the proposed network is assessed via extensive experiments conducted on widely-used benchmarks. The simulation results confirm that the proposed low-light enhancement network outperforms other state-of-the-art approaches. https://github.com/JYP-1317/.