一种针对彩色物体的光栅投影三维测量方法

针对传统彩色编码光栅三维轮廓术中光栅易受到物体表面彩色纹理的干扰,从而造成编码条纹颜色误判和相位误差增大这一问题,提出一种基于互补彩色光栅的三维测量方法,给出了理论分析、光栅设计原理、补偿算法与实验分析。对图像进行初步的解耦校正后,通过预先设计的光栅互补特性,依据彩色响应模型求取物体表面逐点的反射率,并对红绿蓝(RGB)三通道反射率的不平衡进行补偿,消除物体表面彩色纹理的干扰,改善光栅的正弦性。以补偿后的图像来指导彩色编码条纹的分割解码并用傅里叶变换法提取出包裹相位,依据解码结果指导相位展开,继而完成整个三维测量过程。实验证明该方法对彩色纹理的补偿准确有效,降低了彩色纹理对测量的影响。

A Novel Color Fringe Projection Method for 3D Measurement of Colorful Objects

A novel method based on color texture compensation is proposed for three-dimensional (3D) shape measurement of colorful objects. In 3D fringe projection interferometry based on color structured light, color fringe patterns are normally disturbed by the color of the object′s surface. In order to obtain correct fringe order and accurate phase map, a couple of complementary color-encoded fringe patterns are projected onto the surface of object. After decoupling thus the reflectivity matrix of each pixel can be calculated and fringe patterns can be compensated based on the complementary characteristics of the patterns. Wrapped phase map is retrieved through Fourier transform method. Reliable phase unwrapping can be carried out by using the compensated fringe patterns. Experimental results demonstrate the efficiency of the proposed method.