基于亚像素边缘检测和圆心修正补偿的高精度相机标定方法  

High-Precision Camera Calibration Method Based on Subpixel Edge Detection and Circularity Correction Compensation

作　　者：康朝海[1] 洪立 任伟建[1] 霍凤财[1] Kang Chaohai;Hong Li;Ren Weijian;Huo Fengcai(School of Electrical and Information Engineering,Northeast Petroleum University,Daqing 163318,Helongjiang,China)

机构地区：[1]东北石油大学电气信息工程学院,黑龙江大庆163318

出　　处：《激光与光电子学进展》2024年第8期136-144,共9页Laser & Optoelectronics Progress

基　　金：黑龙江省自然科学基金资助项目(LH2023F007)。

摘　　要：基于圆形标定板的相机标定过程中,当镜头畸变较大时图像质量降低、圆形投影边缘模糊,导致标定产生误差。基于此,提出一种基于亚像素边缘检测和圆心修正补偿的高精度相机方法。首先,通过Canny-Zernike矩法提取亚像素级的圆形特征轮廓点,使用边缘点链连接独立轮廓点,得到闭环的精确特征轮廓,增强对模糊边缘轮廓的提取能力;其次,对内外轮廓分别采样取点拟合椭圆,将两者中心的均值作为特征点,并通过三点判断排序法得到有序特征点集后进行粗标定;最后,用粗标定参数对轮廓的采样点集进行校正,重新获取中心坐标后反投影回图像上进行相机精标定,实现畸变情况下的圆心修正补偿标定。实验结果表明,所提方法有效提高了镜头畸变较大时相机标定的精度。During camera calibration process based on a circular calibration board,when the lens distortion is large,the image quality decreases,and the circular projection edge becomes blurry,resulting in calibration errors.Accordingly,a highprecision camera technique based on subpixel edge detection and center correction compensation is proposed.First,the CannyZernike moment method was used to extract subpixellevel circular feature contour points.Moreover,edge point chains were used to connect independent contour points to obtain closedloop accurate feature contours,enhancing the ability to extract fuzzy edge contours.Second,the inner and outer contours were sampled separately,and points were taken to fit the ellipse.The mean of the two centers was used as the feature points,and an ordered feature point set was obtained through the threepoint judgment sorting method for rough calibration.Finally,the rough calibration parameters were used to calibrate the sampling point set of the contour,and the center coordinates were reobtained before backprojection onto the image for precise camera calibration,achieving center correction compensation calibration under distortion.The experimental results show that the proposed method effectively improves the accuracy of camera calibration when the lens distortion is large.

关 键 词：相机标定 Canny-Zernike矩 边缘点链 圆心修正补偿 

分 类 号：O436[机械工程—光学工程]