Light Source Detection in Photographs

Common tasks related to image processing or augmented reality include rendering new objects into existing images, or matching objects with unknown illumination. To facilitate such algorithms, it is often necessary to infer from which directions a scene was illuminated, even if only a photograph is available. For this purpose, we present a novel light source detection algorithm that, contrary to the current state-of-the-art, is able to detect multiple light sources with sufficient accuracy. 3D measures are not required, only the input image and a very small amount of unskilled user interaction.