Recovering lighting in a scene from a single image is a fundamental problem in computer vision. While a mirror ball light probe can capture omnidirectional lighting, light probes are generally unavailable in everyday images. In this work, we study recovering lighting from accidental light probes (ALPs) -- common, shiny objects like Coke cans, which often accidentally appear in daily scenes. We propose a physically-based approach to model ALPs and estimate lighting from their appearances in single images. The main idea is to model the appearance of ALPs by photogrammetrically principled shading and to invert this process via differentiable rendering to recover incidental illumination. We demonstrate that we can put an ALP into a scene to allow high-fidelity lighting estimation. Our model can also recover lighting for existing images that happen to contain an ALP.

翻译：从单个图像中恢复场景的光照是计算机视觉中的一个基本问题。虽然镜面球光探针可以捕捉全方向光照，但在日常图像中，光探针通常无法获取。在本研究中，我们研究从意外光探针（ALPs）中恢复光照，即在日常场景中常见的光滑物体，如可口可乐罐头，在图像中意外出现。我们提出了一种基于物理原理的方法来模拟 ALPs 并从单个图像中估计光照。主要思想是通过摄影测量的原理来建模 ALPs 的外观，并通过可微分渲染来反演这个过程以恢复意外的照明。我们证明了我们可以将 ALP 放入场景中以实现高保真度的光照估计。我们的模型也可以恢复已经存在的图像中包含的 ALP 的光照。