基于亚像素边缘检测融合光照补偿的远心成像标定方法

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关键词：远心镜头标定；亚像素边缘检测；加权迭代圆心拟合；光强误差补偿 中图分类号：TP394.1;TH745.4 文献标识码：A doi：10.37188/OPE.20253316.2578 CSTR：32169.14.OPE.20253316.2578

Telecentric imaging calibration via integrated sub-pixel edge detection and illumination compensation

YUAN Jing 1，2 ， LIN Hu*， SHI Zhaoyao³，WANG Xian1， YANG Guoliang²

1. School ofMechanical and Electrical Engineering，Hunan University ofScience and Technology， Xiangtan 411201， China;2. Division of Dimensional Metrology， National Institute of Metrology，Beijing 1Ooo29， China; 3.Beijing Engineering Research Center of Precision Measurement Technology and Instruments， Beijing University of Technology，Beijing lOol24，China） * Corresponding author，E-mail： linhunim@l63.com

Abstract：To address the high-precision calibration demands of telecentric imaging systems and the inadequacy of traditional pinhole models，this paper proposed a high-accuracy camera calibration method that integrated subpixel edge detection with ilumination eror compensation.First，an improved Gaussian integral curve fiting algorithm extracted subpixel edges of circular calibration targets，with center coordinates precisely determined via weighted iterative least squares. Second，a system magnification equation was derived based on the telecentric model and rotation matrix orthogonality to resolve extrinsic parameter sign ambiguities，accompanied by a disambiguation strategy. Subsequently，radial，tangential，and composite distortion models were constructed and evaluated for characterizing telecentric lens distortion. Distortion parameters were accurately estimated through Levenberg-Marquardt nonlinear optimization. An ilumination error compensation model dynamically updated correction parameters within the calibration pipeline to eliminate edge offset erors. Experimental results show the calibration method achieves an optimal reprojection error of O.O59 pixels，with measurement errors within 1.6μm for CMM probe ball diameter under 15-28 light intensity levels after compensation，validating its effectiveness.

Key words： telecentric lens calibration； subpixel edge detection;weighted iterative circle fiting；compensation for light intensity errors

1引言

相机标定是三维重建和视觉测量等领域的基础性工作，其核心在于通过数学模型精确描述成像过程，并确定相机的内外参数[1-2]。（剩余16823字）