提出一种基于红、绿、蓝和红外并行4颜色通道的条纹投影三维测量技术,实现单次测量获得物体的表面三维形貌。该技术克服了传统方法投影多帧条纹图像而造成测量速度慢的缺点,在保证精度的同时提高了测量速度。结合两步相移、傅里叶变换法和最佳三条纹选择法的相位求解方法,独立计算各个像素点的绝对相位,从单次同时采集的复合彩色图像和红外图像中获得非连续物体等复杂面形的三维形貌数据。利用半透半反镜实现了可见光和红外两个投影仪的光轴同路,并建立它们之间的投影变换,实现了两个投影仪像素间的精确对应。利用所研制的系统,测量了非连续的静态物体和动态物体,获取了它们的表面三维形貌数据。结果显示,所研制的方法适用于三维形貌的快速测量。

We present a three-dimensional (3D) shape measurement technique based on parallel four-color channels (red, green, blue and infrared) fringe projection, which only needs one-time measurement to reconstruct the 3D surface shape of an object. The proposed technique overcomes the shortcomings of slow measurement speed caused by multi-frame fringe images projection in the traditional fringe projection, and possesses high accuracy. Two-step phase shift, Fourier transform with the optimum three-frequency method are combined to calculate the absolute phase point-by-point independently and recover 3D shape measurement of complex objects, such as discontinuities, from the deformed composite color fringe pattern and infrared fringe pattern captured simultaneously. A beam splitter has been used to realize coaxial design and to build the projecting transformation between the visible light projector and the infrared light projectors, so that they build up the accurate pixel-to-pixel correspondence. Several experiments on static and dynamic objects are performed to obtain the 3D shape, and experimental results show that the proposed method is suitable for fast 3D shape measurement.