基于彩色编码相移条纹的相机标定

Camera calibration based on color-coded phase-shifted fringe

针对传统标定方法对靶标特征点模糊噪声适应性低的问题,提出一种基于彩色编码相移条纹的标定方法。以液晶显示面板为标定靶,依次显示水平和垂直彩色编码相移条纹;通过颜色通道分离,得到正交相移条纹;结合相移理论,以正交相位截断线的交点为特征点;多次改变靶标位姿,提取特征点,结合基于平面二维靶标的标定理论,实现单相机与双目立体视觉系统的标定。此外,在靶标图样四角添加彩色编码相移圆环,实现特征点的自动提取与排序,提高标定效率。实验结果表明,在拍摄靶标图像模糊时,单相机标定的重投影误差为0.15 pixels,标定后双目系统的测量标准偏差为0.1 mm。

Aiming at the low adaptability of blurring noise of target feature points in traditional calibration methods,a calibration method based on the color-coded phase-shifted fringe is proposed.Using a liquid crystal display panel as the calibration target,horizontal and vertical color-coded phase-shifted stripes are displayed in sequence;the orthogonal phase-shifted stripes are obtained by separating color channels;based on the phase-shifteg theory,the intersections of the orthogonal phase truncation lines are calculated as the feature points.After changing the target position multiple times and extracting feature points,the plane-based camera calibration technique is applied to realize the calibration of both the single camera and the binocular system.Furthermore,color-coded phase-shift circles are added to four corners of the target pattern to automatically extract and sort feature points.Accordingly,the effi-ciency of calibration is promoted.The experimental results indicate that when the target image is blurred,the reprojection error of the single-camera calibration is 0.15 pixels,and the standard deviation of the binocular system measurement after calibration is 0.1 mm.