Calibration Research on Fish-eye lens

A novel calibration method for fisheye lens camera is proposed in this paper. The method is based on equidistance projection model of fisheye lens. The inner structure of the fisheye lens which consists of many pieces of lens is so complex that it is very difficult and unnecessary to construct its physical model. The optical center of the fisheye lens (u₀,v₀), the virtual focal of the fish-eye lens l and the ration of the distortion in x coordinate Kx and the Ky in y coordinate should be calibrate in the mathematical mode proposed by us. Some special calibration patterns have been designed for calibrating them. Here, the optical center is the precondition for other parameters precise calibration. Therefore, we discuss four different methods to get it. The experiment results show that the methods we present are accurate and stable.