Artificial lights commonly leave strong lens flare artifacts on the images captured at night, degrading both the visual quality and performance of vision algorithms. Existing flare removal approaches mainly focus on removing daytime flares and fail in nighttime cases. Nighttime flare removal is challenging due to the unique luminance and spectrum of artificial lights, as well as the diverse patterns and image degradation of the flares. The scarcity of the nighttime flare removal dataset constrains the research on this crucial task. In this paper, we introduce Flare7K++, the first comprehensive nighttime flare removal dataset, consisting of 962 real-captured flare images (Flare-R) and 7000 synthetic flares (Flare7K). Compared to Flare7K, Flare7K++ is particularly effective in eliminating complicated degradation around the light source, which is intractable by using synthetic flares alone. Besides, the previous flare removal pipeline relies on the manual threshold and blur kernel settings to extract light sources, which may fail when the light sources are tiny or not overexposed. To address this issue, we additionally provide the annotations of light sources in Flare7K++ and propose a new end-to-end pipeline to preserve the light source while removing lens flares. Our dataset and pipeline offer a valuable foundation and benchmark for future investigations into nighttime flare removal studies. Extensive experiments demonstrate that Flare7K++ supplements the diversity of existing flare datasets and pushes the frontier of nighttime flare removal toward real-world scenarios.

中文翻译：

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Flare7K++：混合合成数据集和真实数据集，用于夜间耀斑消除等


人造光通常会在夜间拍摄的图像上留下强烈的镜头耀斑伪像，从而降低视觉算法的视觉质量和性能。现有的火炬清除方法主要侧重于清除白天的火炬，在夜间的情况下会失败。由于人造光的独特亮度和光谱，以及眩光的多样化图案和图像退化，夜间光斑去除具有挑战性。夜间耀斑清除数据集的稀缺性限制了对这项关键任务的研究。在本文中，我们介绍了 Flare7K++，这是第一个全面的夜间耀斑消除数据集，由 962 张真实捕获的耀斑图像 （Flare-R） 和 7000 张合成耀斑 （Flare7K） 组成。与 Flare7K 相比，Flare7K++ 在消除光源周围的复杂退化方面特别有效，而单独使用合成眩光很难解决。此外，以前的光斑消除管道依赖于手动阈值和模糊内核设置来提取光源，当光源很小或没有过度曝光时，这可能会失败。为了解决这个问题，我们还在 Flare7K++ 中提供了光源的注释，并提出了一个新的端到端管道，以在去除镜头眩光的同时保留光源。我们的数据集和管道为未来夜间耀斑清除研究的调查提供了宝贵的基础和基准。大量实验表明，Flare7K++ 补充了现有耀斑数据集的多样性，并将夜间耀斑消除的前沿推向了真实场景。