CCD Image Geometrical Distortion Correct and Large Touch Screen

There are geometric distortions in all the images produced by the CCD camera lens, and the distortions are all nonlinear. Coordinate conversion is an effective method for geometric correction. The calculations will boost as the higher degrees of the polynomial. It is impossible to apply directly in real time correction system. This article introduces a correction according to divided areas through linear polynomial on the base of higher degree polynomial coordinate conversions. In the method the image is divided into uneven loop like areas at first. In each area you can take a linear polynomial approximating higher degree polynomial. Because CCD camera lens distortions are radial distortions, high precision can be acquired through the linear polynomial on the base of higher degree polynomial. In the same time the calculations can be decreased and meet the needs of real-time correction. Apply this method on large touch screen, it can correct the distortion effectively and is useful in engineering.