Image Processing Research Of Spherical Lenses Surface Shape Deviation Detection

In the process of detecting the optical lens,to avoid causing the secondary wear for the lens,optical interferometry is usually used to realize non-contact spherical surface shape deviation detection,so this article mainly studies image processing methods of the interference fringe.This study aims to lay the software foundation for non-contact automatic detecting the spherical optical lens surface shape deviation by processing the interference fringe to get phase quantitative distribution information and fitting the wavefront of the optical lens.Paper introduces the evaluation index of optical surface shape deviation,and emphasizes the image processing method of the interference fringe and wavefront fitting method.This article does the algorithm research with processing the national standard interference patterns and the interferograms from Zygo interferometer.Firstly it selected the best solution of the interference fringe pretreatment by contrastive study,and given the contrast analysis of gray threshold method and two-dimensional derivative binary diagram method.According to the spherical optical lens are almost circular aperture,fitting the circular boundary with least squares is to get the center coordinate and the radius of data,and the boundary wave aberration are obtained by spline interpolation.Then wavefront fitting is respectively used the Zernike polynomial and Multi-quadric interpolation.The last step is calculating the value of EPV and ERMS and comparing the results with national standard data and the test results of Zygo interferometer,and providing the reasons of error.Finally it summarized the research work and prospect has been put forward.