单幅彩色条纹投影的不连续物体表面三维形貌测量

Single Color Fringe Projection for Measuring Three-Dimensional Shapes with Discontinuities

提出了基于单幅彩色条纹投影的不连续物体及动态三维形貌的测量方法。该方法利用计算机产生一幅正弦条纹图和两幅单一强度图分别通过红蓝绿三个通道合成为一幅彩色条纹图,由液晶投影仪投影到被测物体表面,彩色CCD采集变形条纹图并保存在计算机中。通过三色分离,同时获得正弦条纹图和反映表面反射率分布及背景信息图,通过图像除法运算及亚像素精度归一化处理实现物体三维形貌的恢复。对于表面形貌不连续的物体,利用蓝色分量的灰度图像进行二值化处理定位阴影或暗背景,从而引导正确的相位求解。实验验证了该方法对不连续物体动态测量方面的可行性。

A novel fringe projection profilometry used for discontinuous shape measurement is proposed.One color fringe pattern generated by computer encoding with a sinusoidal fringe and two uniform intensity patterns is projected by a digital video projector and the deformed fringe pattern is recorded by a color CCD camera.The captured color fringe pattern is separated into its RGB components and division operation is applied to red and blue channels to reduce the variable reflection intensity.Shape information of tested object is decoded by applying an arcsine algorithm on the subpixel-scale normalized fringe pattern.To determine the shadow and dark background,the separated blue component is binarized and used to guide the phase extraction.The experimental results demonstrate the validity of the proposed method for discontinuous and dynamical shape measuring.