数字光栅投影轮廓测量系统不确定视角标定法

Unknown orientation views calibration for digital fringe projection profilometry

建立了数字光栅投影轮廓测量系统的简易标定模型,以实现测量系统的简便化和便携式应用。该标定模型基于绝对相位提取和空间映射技术,仅需确定像面坐标和绝对相位到空间坐标的转换矩阵。标定矩阵由L evenberg-M ar-quardt算法优化求解,其中所需的已知空间点阵列借助新型虚拟三维靶标实现。该虚拟靶标基于不确定视角摄像机标定法,仅需要一个平面靶标,避免了使用昂贵的平移设备,极大地降低了标定系统的成本和复杂度。对标定系统进行了大量实验,并使用标定球对测量系统进行了测量精度评价。实验结果表明标定精度高于0.2mm,证明该标定法具有很好的应用价值。

A simple calibration model was developed for digital fringe projection profilometry （DFPP） based on absolute phase extraction and space mapping techniques to simplify the measuring system. The calibration model only depends on the conversion matrix from the image coordinates and the absolute phase to space coordinates. The calibration matrix can be solved by Levenberg-Marquardt optimization. A virtual space pattern is used to provide the point array with given coordinates using unknown orientation views camera calibration theory. The one-plane pattern differs from the virtual space pattern which needs an expansive translation device. Experimental results show that the economical method is easier with a calibration precision of 0.2 ram. Therefore, the method can be widely used in other computer vision fields.