A flying grey ball multi-illuminant image dataset for colour research

For research in the field of illumination estimation and colour constancy, there is a need for lots of ground truth measurements of the illumination colour at numerous locations within multi-illuminant scenes. A practical approach to obtaining such ground truth illumination data is presented here. The proposed method involves using a drone to carry a grey ball of known percent surface spectral reflectance throughout a scene while photographing it frequently during the flight using a calibrated camera. The captured images are then post-processed. In the post-processing step, machine vision techniques are used to detect the grey ball in each frame. The colour of the grey ball then provides the illumination colour at that location. In total, the dataset contains 30 scenes with 100 illumination measurements on average per scene. The dataset has been made publicly available for download.