非静态物体的光栅图像投影3D测量方法

针对传统相移法不能直接应用于非静态物体三维(3D)形貌测量的问题,本文提出了 Morlet 小波辅助的改进相移法测量方法。 首先,利用复 Morlet 小波脊线提取采集条纹图像的相位,估算图像帧之间的相位变化量,并根据帧间相位变化量来修正相移法的计算模型。 然后,利用修正的计算模型,提取采集光栅图像的相位,并重建出非静态被测体的 3D 形貌。 在对视场范围内的非静态被测体,本文方法测量的均方根误差为 0. 0816 mm,分别是传统相移法和单帧投影法的 16. 92%、44. 42%,在对比方法中误差最小。 测量结果表明,本文方法拓展了相移法适用的范围,能够更准确测量非静态被测体的 3D 形貌。

3D measurement method using grating image projection for non-static object

To deal with the problem that the traditional phase-shifting (PS) method cannot be used to measure the three-dimension (3D)shape for a non-static object, a grating image projection-based method which combines the improved PS method with the Morlet waveletsis proposed. First, the phase of grating image is extracted by the Morlet complex wavelet ridge, the phase variation between image framesis estimated, and the calculation model of the phase-shifting method is modified according to the phase variation. Finally, the phase ofthe captured grating image is extracted using the modified calculation model, and the 3D shape of the non-static object is reconstructed.The root-mean-square (RMS) error of the proposed method is 0. 081 6 millimeter for a non-static measurement object in the field ofview. The RMS error of the proposed method is 16. 92% and 44. 42% of the PS method and the single frame projection method,respectively, and is the smallest among the comparison methods. According to the measurement result, the proposed method expands theapplication scope of the PS method, and can measure the 3D shape for a non-static object accurately.