A method to distinguish road surface conditions for car-mounted camera images at night-time

Many conventional distinction methods of road surface condition using car-mounted cameras have been already proposed. However, most of these methods are only effective for daytime and bright conditions. Therefore, we need to expand these methods for impractical night-time that is much more dangerous environment. In this paper, we propose a new distinction method for road surface conditions at night-time, such as dry, wet and snow. This method uses only video information acquired by an inexpensive car-mounted video camera and uses the difference in road surface features for each condition. The image features of the road surface are depending on the illuminant conditions such as street lamps, signal lights, reflections and other lighting sources. Therefore, we analyze the image features based on color information and the presence of other light sources. As a result, the distinction of road surface conditions was achieved with high accuracy, including the areas illuminated by street lamps and other light sources.