Distortion model selecting and accuracy evaluation for CCD camera calibration

This paper presents that the precision of CCD camera calibration depends on both distortion models selected and signal-to-noise. The former is called intrinsic factor, and latter is called extrinsic factor. So far, none of fixed criterion has been used as selecting distortion model, and almost all are personal or experiential, None of fixed criterion has been used as determining with how much error we measure 2D image coordinates, the calibration model can correctly compensate for the distortion in a fixed imagery system in current calibration methods. The paper presents using notable check and correlation coefficient check in statistics to select distortion model, using signal-to-noise ratio, which is a proportion about distortions in data noise, as criterion to measure compensation capability: A large number of simulant and practical experiments show (1) Various distortion models are existed in various imagery system; (2) There exist high correlation among distortion parameters or between distortion parameters and camera parameters; In addition, (3) the larger the signal-to-noise ratio is, the larger the compensation capability is, On the contrary, the smaller signal-to-noise ratio is, the smaller the compensation capability is; (4) the relation between precision improving and signal-to-noise ratio is exponential function.