摘要
为了扩展准直测量的应用领域,提高测量范围是最为有效的手段之一,因此用于准直测量的鱼眼相机应运而生。针对准直测量用鱼眼相机标定精度不高的问题,提出了一种基于插值形式的径向粗标定及基于栅格形式的补偿精标定的两步式准直测量用鱼眼相机标定方法。该方法使用插值而并非构建成像模型,能够有效避免模型不准确及参数设置不合理而引入的系统误差,并且可以在一定程度上抑制镜片加工的非对称性及光学系统装调所带来的偏差。区别于图像评价的峰值信噪比(PSNR)以及结构相似性(SSIM)等性能指标,该方法选择的平均重投影误差(MRE)这一指标能够更有效地衡量准直测量使用条件下相机标定结果的优劣。仿真对比实验结果表明该方法在4种虚拟鱼眼相机模型上的标定效果皆优于传统标定方法,与传统的方法相比,标定的不确定度最大能够改善82.63%。样机标定实验结果表明,该方法能够有效标定真实的准直测量用鱼眼相机,在搭建的真实样机上应用该标定方法后,样机的入射矢量解算的不确定度能够提升至角秒级。
Objective Collimation measurement is one of the most widely used precision angle measurement and attitude measurement methods.By imaging the known reference target at infinity,the accurate angular relationship between the measured object and the reference target can be obtained.The measurement results have the advantages of high accuracy and high repeatability.Photoelectric autocollimator,electronic total station,theodolite and other measuring and calibration instruments all take collimation measurement as their main measurement principle.Due to the limitation of the calibration accuracy of the large-field-of-view and highdistortion optical system,the camera field of view used in precision collimation measurement is usually small,so there are great limitations in the application of large range angle measurement.Fisheye camera has the advantages of large field of view,small volume and light weight,so it should have a broad development prospect in the field of measurement and calibration.However,due to the large field of view and large distortion of the fisheye camera,there is a complex nonlinearity in the camera imaging process,and the asymmetry in lens processing has a more severe impact on the imaging model parameters.For this reason,a fisheye camera calibration method for high precision collimation measurement is proposed in this paper.Methods A two-step fisheye camera calibration method for collimation measurement is proposed in this paper,which includes radial rough calibration based on interpolation and fine calibration based on grid compensation.This method uses interpolation instead of constructing camera model,which can effectively avoid the system error caused by inaccurate model and unreasonable parameter setting,and can restrain the asymmetry of lens processing and the deviation caused by optical system adjustment to a certain extent.Different from the commonly used performance indicators such as peak signal-to-noise ratio(PSNR)and structural similarity(SSIM),the mean reprojection error(MRE)selected in
作者
熊琨
何旭然
王春喜
李佳宾
杨长浩
Xiong Kun;He Xuran;Wang Chunxi;Li Jiabin;Yang Changhao(Beijing Aerospace Institute for Metrology and Measurement Technology,Beijing 100076,China)
出处
《红外与激光工程》
EI
CSCD
北大核心
2024年第2期109-119,共11页
Infrared and Laser Engineering
关键词
准直测量
鱼眼相机
标定
畸变矫正
collimation measurement
fisheye camera
calibration
distortion correction
