Abstract: Since the fish-eye camera has wide view field, it has been used widely in many fields.
However, there is seriously radial distortion, needed to be corrected before any application. Fish-eye
image geometric correction is a hot and difficult problem in current industrial applications and theoretical
research. This paper presents a radial distortion model, and point out its analytical solution is not unique.
According the symmetry of the radial distortion, reveals the relationship between a distortion curve and its
ideal straight line, called the analytical expression of the curve distortion correction. Based on the previous
analysis, this paper proposes a geometric correction method. Experiments show that this method is simple,
can effectively corrects the scene which containing line features.

Key words: radial distortion, fish-eye image, geometric correction, distortion correction