Today's traffic environment, such as traffic and information signs, road markings, and vehicles, is designed for human visual perception (even if first approaches for automatic evaluation by electronic sensor systems in the vehicle exist -see chapter "▶ Intersection Assistance"). This is done by different shapes, colors, or a temporal change of the signals.It is therefore a good choice to use a system similar to the human eye for machine perception of the environment. Camera systems are ideal candidates as they offer a comparable spectral, spatial, and temporal resolution. In addition to the "replica" of human vision, specific camera systems can provide other functions, including imaging in infrared spectral regions for night vision or a direct distance measurement.This chapter covers details on specific applications of camera-based driver assistance systems and the resulting technical needs for the camera system. Use cases covering the outside and inside of the vehicle are shown. The basis of every camera system is the camera module with its main parts -the lens system and the image sensor. The underlying technology is described, and the formation of the camera image is discussed. Moving to the system level, basic camera architectures including mono and stereo systems are analyzed. The chapter is completed with a discussion of the calibration of camera systems.
ApplicationsDue to their versatility, camera systems in automobiles are used both for surveillance of the interior of the car as well as the surroundings (Loce et al. 2013). The following section discusses these applications and explains the specifics of using camera systems for these.A first driver assistance system using a camera system was the so-called rear view camera. The driver is assisted by the display of a live video stream on a monitor system. Advanced functions using computer vision are, for example, used in the high-beam assist function. In these systems, the video image is not displayed, but a specific function is directly derived from the camera image.In addition, cameras are used in the interior of the vehicle. Here, two main functions are of importance. First, the driver monitoring for detecting the state of the driver and the driver's intention and, secondly, the use of camera systems in the context of an advanced man-machine interface for controlling functions, for example, by means of gesture and gaze control.