Fringe-Aided Specular Projection Moiré Method for Multi-Area 3D Morphology Measurement

The specular surfaces often exist as multi-areas in industries and require high-precision morphology measurement. This letter proposes a fringe-aided specular projection moiré method for multi-area specular morphology measurement. A strategy for moiré component selection is developed to generate the optimized moiré pattern for different types of mirrors. Additionally, an identification method based on windowed Fourier transform is introduced to detect specular regions. Thus, the principle of the fringe-aided specular projection moiré method is proposed. An experiment is carried out to validate the method’s performance, where a mirror array consisting of two concave and one convex is measured. The results show that the proposed method is able to recognize specular areas and extract the wanted moiré patterns for different mirrors, and the method achieves micron-level precision in morphology measurements.