A Vehicle-mounted Panorama System Based On Fish-eye Cameras

Cars are becoming more and more common in Chinese families as a consequence of the booming domestic economy. Although the amount of traffic accidents has been deceasing in recent years, the growing number of cars remains a challenge. Maturity of traffic laws and development of security awareness both contribute to this decrease in traffic accidents. In addition to them, many kinds of driver assistance systems also help us a lot.Among all kinds of driver assistance systems, systems based on cameras and ultrasonic are most common ones. Combined with cameras, this kind of systems use the principle of sonar to detect obstacles and give driver the efficient information about the car and its surroundings. The sonar part of those systems is mature enough, however, the visual part of them still needs improvement. So in this thesis we devise a vehicle-mounted panorama system based on fish-eye cameras in which four fish-eye cameras are used to provide a bird’s eye view with 360-degree angle in horizontal. This system can achieve the same performance while using less cameras compared with other systems. Since four images are merged into one, it will be more natural and user-friendly than other systems in which drivers need to focus on several pictures. The following procedures are included to fulfill this system:(1)Design the experiment to capture images using four fish-eye cameras. The cameras are placed in four edges of a virtual rectangle representing a car.(2)Use a concentric circles template to calibrate the images taken by fish-eye cameras because the images contain distortion.(3)Change the perspective of images calibrated using perspective transformation. The perspective is changed to one which is perpendicular to the ground and downward. In this procedure, a method is raised to identify the markers in images automatically.(4)After perspective transformation, do reverse calibration and then merge four images into one to give a bird’s eye view with 360-degree angle in horizontal.The system turns out to be robust, user-friendly and has good prospects in applications.