Detecting Unfocused Raindrops: In-Vehicle Multipurpose Cameras

Advanced driver assistance systems (ADASs) based on video cameras are becoming pervasive in today´s automotive industry. However, while most of these systems perform nicely in clear weather conditions, their performances fail drastically in adverse weather and particularly in the rain. We present two novel approaches that aim to detect unfocused raindrops on a car windshield using only images from an in-vehicle camera. Based on the photometric properties of raindrops, the algorithms rely on image processing techniques to highlight them. The results will be used to improve ADAS behavior under rainy conditions. Both approaches are compared with each other and the techniques from the literature.