基于自标定技术的相机内方位元素测试影响因素分析

Analysis of Camera Intrinsic Parameter Testing Factors Based on Self-calibration

内方位元素测试精度对于航天相机至关重要,可以有效提高图像的几何质量,需作重点分析。传统航天相机内方位元素标定方法一般采用光电精密测角法,该测试方法通过旋转相机的方式实现高精度的内方位元素和畸变测试,对测试设备的精度和承重要求较高,具有应用局限性。相机自标定技术方法灵活,仅需建立图像点和网格板角点之间的对应关系,无需复杂、精密的测试设备便可直接求解出内方位元素。本文从自标定算法的推导中,分析基于自标定技术的内方位元素测试精度的影响因素,通过实际标定试验归纳出达到理想标定精度时各个影响因素的最优值。

The measurement accuracy of intrinsic parameters is important for satellite camera and can effectively enhance the geometric accuracy of images,so it should be analyzed seriously. The traditional testing method of satellite camera intrinsic parameters usually is photoelectrical precise angle measurement,this testing method realizes high accuracy intrinsic parameters and distortions testing,at the same time,the method requires high accuracy and heavy supporting testing instrument which is limited in practice. Camera self-calibration technology is flexible,and only need to build the relationship between the image points and corner points on grid pattern without complicated and accurate testing instruments to directly solve the intrinsic parameters. In the processes of inducing the algorithms of the self-calibration technology,we analyze some factors that affect the calibration results of the intrinsic parameters based on self-calibration. Through practice calibrations we get the best values of every affecting factors when achieve the ideal calibration accuracy.