变焦相机自标定方法研究-《郑州大学学报(工学版)》

文章信息/Info

Title:: Zoom Camera Self-calibration Method Based on Two Vanishing Points(PD)

Author(s):: Zhao Shujun; Duan Shaoli; Zhang Xiaofang; Li Lei; Liu Xiaomin; School of Physical Engineering, Zhengzhou University, Zhengzhou, Henan 450001

Keywords:: Zoom camera calibration; Two vanishing point; Sub-pixel comer detection; Zoom center; The optical center displacement

摘要:: 研究了变焦式相机的标定方法,采用基于二消失点的自标定方法对变焦摄像机的两个固定焦距下的一般参数进行标定,通过与张正友标定方法、机器视觉软件Halcon标定的结果进行比较,验证了该方法的可行性和鲁棒性.为了能够更好地反映变焦相机的变焦特性,建立了能更精确描述变焦摄像机的厚透镜模型.笔者通过对变焦图像进行SIFT特征匹配,根据匹配点对建立直线方程组,采用最小二乘方法估计变焦图像的缩放中心,另外,还计算了不同焦距之间的光心位移.实验结果表明,光心位移与焦距的变化量有明显的差距,从而说明厚透镜模型更适合用来描述摄像机的变焦镜头.

Abstract:: The calibration method of the zoom camera is studied. The self-calibration method based on the two vanishing points is used to calibrate the general parameters of the zoom camera under two fixed focal lengths. By comparing with Zhang Zhengyou’s calibration method and the results of the machine vision software Halcon calibration, the results are verified. The feasibility and robustness of this method are verified. In order to better reflect the zoom characteristics of the zoom camera, a thick lens model that can more accurately describe the zoom camera is established. The author performs SIFT feature matching on the zoom image, and according to the matching point pair The linear equations are established, and the least square method is used to estimate the zoom center of the zoom image. In addition, the optical center displacement between different focal lengths is also calculated. The experimental results show that there is an obvious gap between the optical center displacement and the focal length, which shows that The thick lens model is more suitable for describing the zoom lens of the camera.