逐像素调制的高反光表面三维测量方法

Three-dimensional measurement method of highly reflective surface based on per-pixel modulation

高反光表面的三维面形测量是光学三维测量领域的难题之一,本文提出一种基于逐像素调制的高反光表面三维测量方法,可解决光学三维测量中因过度曝光而导致的相位信息无法获取的问题。首先,通过投影最大灰度值的灰度图识别饱和像素点的位置;然后,依据投影低灰度下横纵条纹图进行过饱和区域坐标匹配,并结合一种新的相机-投影仪强度映射关系,逐像素求解过饱和像素点的最佳投影灰度值;最后,投影重新生成自适应条纹投影序列,并结合多频外差相移法用于相位恢复和三维重建。实验结果表明:所提方法的间距平均误差和标准偏差均小于文中其他方法所得的测量值,相对于传统方法,该方法的平均误差减少了61.9%,标准偏差减少了67.7%。本文所提方法的调制度高,速度快,能保证很高的测量精度。

The three-dimensional(3D)shape measurement of highly reflective surface is one of the common problems in the field of optical 3D measurement.In this paper,a 3D measurement method of highly reflective surface based on per-pixel modulation was proposed to solve the problem that the phase information could not be obtained due to overexposure.Firstly,the positions of saturated pixels were identified by the projecting maximum gray image.Then,the coordinate matching was carried out by projecting horizontal and vertical fringes under low gray-level condition,and the optimal projecting gray value of supersaturated pixels would be per-pixel modulated by combining with a new intensity mapping relationship between camera and projector.Finally,the reconstructed and adaptive fringe projection sequences were projected,phase recovery and 3D reconstruction were realized by using the multi-frequency heterodyne phase shift method.The experimental results showed that the average error and standard deviation of the proposed method were less than the measured values obtained by other methods,and compared with the traditional method,the average error was reduced by 61.9%and the standard deviation was reduced by 67.7%.The proposed method has the advantages of high modulation,fast speed and can ensure high measurement accuracy.