Effective Factors Analysis on Camera Calibration

This paper conducted some experiments to analyze three effect factors on camera calibration, which includes light intensity variation, chessboard planarity and image number. Firstly, three factors are discussed to quantify their effect on calibration accuracy. For convenience of analysis, camera calibration process and methods are explained in detail. Then, error model is constructed by deriving from perspective equation. Finally, some related experiments are conducted under different conditions. Experiments show that light intensity has less effect on feature extraction of chessboard corner. Therefore, its effect could be neglected on calculation accuracy. On the contrary, the world coordinate of chessboard corner is one of main effect factors on camera calibration. In other words, more attentions should be paid to chessboard planarity for improving calibration accuracy. Furthermore, it can be found that position of main point inevitably varies with the increasing of image number and effective focal length. Experiment results point out that the calculation accuracy and efficiency of inner parameters will become more ideal under condition of image number of 17~24.