CAJ | 학술논문

CCD摄像机的标定是实现光学三维轮廓测量技术的必要步骤，其标定精度在很大程度上取决于标定特征点的定位精度．在分析现有棋盘格角点像素级和亚像素级定位方法不足的基础上，提出了一种基于改进SV方法的棋盘格角点亚像素定位方法．首先，采用SV算子对角点进行像素级检测；其次，选取标定图像中以初定位角点坐标为中心的5×5像素区域，对其灰度值进行双线性插值；最后，计算插值图像的灰度质心，再根据插值放大倍数，将质心转换到亚像素坐标，实现了角点亚像素定位．实验结果表明，该方法可以获得亚像素级角点坐标，实现CCD摄像机的高精度标定，标定平均误差为0．108 mm．
CCD섭상궤적표정시실현광학삼유륜곽측량기술적필요보취，기표정정도재흔대정도상취결우표정특정점적정위정도．재분석현유기반격각점상소급화아상소급정위방법불족적기출상，제출료일충기우개진SV방법적기반격각점아상소정위방법．수선，채용SV산자대각점진행상소급검측；기차，선취표정도상중이초정위각점좌표위중심적5×5상소구역，대기회도치진행쌍선성삽치；최후，계산삽치도상적회도질심，재근거삽치방대배수，장질심전환도아상소좌표，실현료각점아상소정위．실험결과표명，해방법가이획득아상소급각점좌표，실현CCD섭상궤적고정도표정，표정평균오차위0．108 mm．
CCD camera calibration is a necessary procedure to realize optical 3 D profile measurement,its accuracy depends on the positioning accuracy of feature points in a great degree.A high accuracy corner detection method based on improved SV algorithm was proposed,through analyzing the deficiency of the existing methods to detecting black and white checkerboard corner points.Firstly,the corner points were detected in pixel level using the operators of symmetry and variance.Secondly,the simple gray bilinear interpolation was used for the area of a 5 ×5 window,whose center was the initial location corner in the photographed checker calibration image.Finally,centroid algorithm was adopted in the areas of each corner neighborhood after interpolation to obtain gray centroid coordinates.According to the amplification factor,centroid coordinates were located to sub -pixel corner coordinates corresponding to the calibration image.The experiment prove the validity of the proposed method,which locate sub -pixel corner coordinates ,also can realize the high CCD calibration accuracy.The experiment results show that the average error of CCD calibration is 0.108 mm.