Visibility Estimation under Night-time Conditions using a Multiband Camera

Various driver-assistance systems are currently being developed that make use of on-vehicle cameras. However, the imaging conditions and the methods used to detect objects are different for each system. Therefore, a special camera is often needed in order to satisfy the requirements of each system. A camera that can be shared by multiple systems will become essential when more systems are put to practical use in the future. Therefore, a multiband camera has been developed that can provide both color images and near-infrared images. The camera includes a special filter that improves on the Bayer filter arrays that are used in single-chip digital color cameras, and it can simultaneously obtain images covering four wavelength bands that have the same optical axes and fields of view. Moreover, a method for estimating the driver's visibility when using the camera is described in this paper.