Overview: Due to the large dynamic range and high precision, the optical 3D measurement technology based on phase calculation is widely used in aerospace, automobile manufacturing, biomedicine, cultural relics protection, and other fields to measure a type of surface. For example, fringe projection profilometry and phase measurement deflectometry are used to measure diffuse and specular surfaces, respectively. With the development of advanced manufacturing technology, the measurement of one type of surface cannot meet the current situation. In the existing research on diffuse and specular composite surfaces, 3D topography restoration of large gradient and discontinuous composite surfaces has been achieved. The composite surface measurement system based on fringe projection and fringe reflection can obtain absolute phase rapidly through the multi-color channel of the camera. However, the multi-color channel of the camera not only realizes the rapid measurement but also introduces the errors such as crosstalk and chromatic aberration into the system, which limits the accuracy of 3D topography restoration of composite surface objects. Crosstalk mainly comes from the process of simultaneously shooting different color stripes projected by the projector to the diffuse part of the object and displayed by the transparent display screen on the mirror part of the object. The color difference mainly comes from the different color stripes displayed by the double screen transmission of the mirror part, and there is a phase difference between the absolute phase of the two colors. Therefore, this paper studies the crosstalk elimination method based on the matrix and the color difference elimination method of absolute phase corresponding pixel deviation. Based on the crosstalk matrix, the crosstalk matrix of the projector and the transparent screen is calculated respectively according to the color light intensity relationship between the color camera, projector, and transparent screen. The stripes of different colors projected on the diffuse surface and mirror of the composite object are separated, and the absolute phase of the two parts is obtained. The absolute phase in the horizontal and vertical directions of each color channel was obtained by color orthogonal stripes, and the relationship between phase difference and pixel deviation between color channels was established to complete the pixel matching of different color channels. Finally, the pixel matching points are converted into the matrix obtained by two-dimensional interpolation to realize the pixel deviation correction of each pixel point and eliminate the influence of color difference. The experimental results show that the proposed method reduces the root mean square error of the composite step from 0.479 mm to 0.030 mm, and improves the measurement efficiency and accuracy.

光学三维测量技术以其非接触、无损及快速测量的优势被广泛应用于不同领域。已有的条纹投影和条纹反射测量术分别适用于漫反射表面和镜面表面。然而，航空航天和先进制造中存在许多漫反射和镜面反射表面同时存在的复合反射表面。提出一种基于结构光投影和反射的方法来实现复合表面形貌的快速测量。首先，投影仪投射蓝色正弦条纹图于被测物体表面，同时显示屏显示的红色条纹被镜面部分反射。其次，彩色相机采集经被测表面调制的变形条纹图。然后，从相机不同颜色通道中提取对应不同类型反射表面的变形条纹，并计算变形条纹图的绝对相位。最后，通过系统标定建立相位信息与深度之间的直接关系，得到被测复合表面的三维形貌。实验结果表明：该方法不仅能够有效地实现非连续复合表面物体的测量，还能够同时测量独立的漫反射和镜面反射表面的三维形貌。