基于镜面和漫反射面标定板的系统参数标定

System parameter calibration based on a specular and diffuse calibration plate

为获取同一像素点镜面反射和漫反射两种反射特性的相位信息和标定数据,实现兼具镜面和漫反射面的复合表面物体三维形貌的全场测量,进而扩大测量范围,提出一种基于镜面/漫反射面标定板的系统参数标定方法。设计并制作镜面/漫反射面标定板,该标定板呈棋盘格样式,其表面带有相邻距离已知的标识。基于镜面/漫反射面标定板的特殊构型,通过限位平移的方式,结合外参约束和样条插值算法以融合获取完整参考相位。在同一坐标系下,逐像素标定空间距离、系统参数、像素位置和横向坐标XY间的映射关系。最后,利用完整参考相位和逐像素标定数据重建复合表面物体的三维形貌。实验结果表明:与非全场测量相比,基于镜面和漫反射面标定板的参数标定方法的测量范围扩大了1.5~2倍。该方法在不牺牲精度的同时,实现了非连续复合表面物体三维形貌的全场测量,扩大了测量范围,对复合表面物体的三维形貌测量有实际应用价值。

To achieve full-field measurement of composite surface objects and expand the measurement range,this paper proposes a system parameter calibration method using a specular and diffuse calibration plate.This method captures phase information and calibration data for both specular and diffuse reflections at the same pixel point.Initially,a specular and diffuse calibration plate with a checkerboard pattern and known marker distances is designed and manufactured. Using the unique configuration of the calibrationplate, the complete reference phase is derived through external parameter constraints and spline interpola⁃tion, facilitated by limit translation. Subsequently, spatial distance, system parameters, and the relation⁃ship between pixel position and horizontal coordinates XY are calibrated pixel-by-pixel within the same co⁃ordinate system. The 3D morphology of the composite surface object is then reconstructed using the com ⁃plete reference phase and pixel-by-pixel calibration data. Experimental results indicate that this method ex⁃tends the measurement range by 1.5-2 times compared to traditional non-full-field methods. The proposedapproach not only maintains measurement accuracy but also enables full-field measurement of 3D morphol⁃ogy of discontinuous composite surfaces, proving to be of significant practical value for measuring the 3Dmorphology of composite surface objects.