改进的复合光栅投影快速三维测量方法

Modified Phase Measuring Profilometry based on Color-encoded Fringe Projection

提出一种新相移算法下的复合光栅投影三维测量方法.利用逆推法建立投影光栅模型,对投影仪投出的光栅进行预校正,保证投到参考面的条纹为标准的正弦分布.测量过程由具有相移的复合光栅到待测物体表面,CCD相机采集变形条纹图,将采集到的图像分离成3帧单色图,再由相位算法提取相位,通过高度映射公式恢复待测物体的三维面形.该方法有较好的抗噪性能,为动态在线测量奠定了基础.计算机仿真实验验证了该方法的可行性.

A new method for 3D measurement of color-encoded grating projection based on a new phase shifting algorithm is presented. First of all, the inverse-deducing method is used to set up the grating model for projection. Then, according to the established model, the projected grating can be pre-corrected in order to ensure that the intensity of the stripe projected on the reference surface is up to a standard sinusoidal distribution. When measuring, after projecting the compound grating with phase shifting to the object, the deformed fringe which can be separated to three monochromatic images is captured by CCD, and then, the phase distri- bution will be extracted so as to recover three-dimensional shape of the object according to the height mapping formula. This proposed method has strong noise resistance and shows high performance in case of adding great noise to the image, which is much helpful for dynamic online measurement. The feasibility of the method is verified by computer simulation experiment.