Establishment and analysis of the diffraction bidirectional reflection distribution function model for surface defects

The purpose of this paper is to establish a diffraction Bidirectional Reflection Distribution Function (BRDF) model of surface defects including scratches and pits, and to analyze the model being applied in various fields. By using nonparaxial scalar diffraction theory, a coherent window function filtering method is proposed, which can obtain the BRDF model of surface defect diffraction under incoherent light conditions. The effectiveness of the model is verified in related work, and the scattering characteristics of surface scratches and pits are obtained. The method and the results obtained by the model have high value in surface defect detection, surface defect stray light analysis and image rendering technology.