Low-Cost Imaging Photometer and Calibration Method for Road Tunnel Lighting

A camera-based measuring instrument for road tunnels lighting is proposed. The system is aimed at estimating the veiling luminance as it will be perceived by a driver approaching the tunnel, thus allowing the estimation of the optimum luminance level of tunnel entrances, hence increasing the driver's safety. The proposed measuring instrument and the relative calibration method are based on a low-cost commercial grade camera and a reference standard, respectively.