  Most algorithms in 3D computer vision rely on the pinhole camera model
because of its simplicity, whereas virtually all imaging devices introduce
certain amount of nonlinear distortion, where the radial distortion is the most
severe part. Common approach to radial distortion is by the means of polynomial
approximation, which introduces distortion-specific parameters into the camera
model and requires estimation of these distortion parameters. The task of
estimating radial distortion is to find a radial distortion model that allows
easy undistortion as well as satisfactory accuracy. This paper presents a new
radial distortion model with an easy analytical undistortion formula, which
also belongs to the polynomial approximation category. Experimental results are
presented to show that with this radial distortion model, satisfactory accuracy
is achieved. An application of the new radial distortion model is non-iterative
yellow line alignment with a calibrated camera on ODIS, a robot built in our
CSOIS.
