  The following three factors restrict the application of existing low-light
image enhancement methods: unpredictable brightness degradation and noise,
inherent gap between metric-favorable and visual-friendly versions, and the
limited paired training data. To address these limitations, we propose an
implicit Neural Representation method for Cooperative low-light image
enhancement, dubbed NeRCo. It robustly recovers perceptual-friendly results in
an unsupervised manner. Concretely, NeRCo unifies the diverse degradation
factors of real-world scenes with a controllable fitting function, leading to
better robustness. In addition, for the output results, we introduce
semantic-orientated supervision with priors from the pre-trained
vision-language model. Instead of merely following reference images, it
encourages results to meet subjective expectations, finding more
visual-friendly solutions. Further, to ease the reliance on paired data and
reduce solution space, we develop a dual-closed-loop constrained enhancement
module. It is trained cooperatively with other affiliated modules in a
self-supervised manner. Finally, extensive experiments demonstrate the
robustness and superior effectiveness of our proposed NeRCo. Our code is
available at https://github.com/Ysz2022/NeRCo.
