Method for measuring lens distortion

Abstract

A new method for measuring glass lens distortion based on using distortion-free pinhole lens is proposed, where the measure of the distortion progress is derived by comparing two images of the calibration field given by pinhole lens and glass lens. Such a simple procedure of lens calibration is advantageous as no additional parameters, that could influence the reliability of the estimation, have to be considered. Those additional parameters are usually the elements of EO which in certain camera component configurations highly correlates with the lens distortion characteristics. Furthermore, such an approach based on measuring relative values given by the comparison of two images do not require absolute position of the calibration field targets which reduces additional sources of error given by target surveying. Particularly, the lens distortion variation induced by change in magnification or aperture can be easily obtained. The proposed method for measuring lens distortion is applied in an experimental investigation leading to the confirmation of the validity of the theoretical development. The result of the investigation derives a promising new possibility for accurate lens calibration.

A new method for measuring glass lens distortion based on using distortion-free pinhole lens is proposed, where the measure of the distortion progress is derived by comparing two images of the calibration field given by pinhole lens and glass lens. Such a simple procedure of lens calibration is advantageous as no additional parameters, that could influence the reliability of the estimation, have to be considered. Those additional parameters are usually the elements of EO which in certain camera component configurations highly correlates with the lens distortion characteristics. Furthermore, such an approach based on measuring relative values given by the comparison of two images do not require absolute position of the calibration field targets which reduces additional sources of error given by target surveying. Particularly, the lens distortion variation induced by change in magnification or aperture can be easily obtained. The proposed method for measuring lens distortion is applied in an experimental investigation leading to the confirmation of the validity of the theoretical development. The result of the investigation derives a promising new possibility for accurate lens calibration.