The Simulation Study On Point Spread Function Of Grating Image

As an optical device,grating is more and more valued and applicated in the field of imaging.But in its imaging process it is often accompanied by serious aberrations,which is the most important factor restricting its development.Therefore,this paper uses the method of digital image processing to analyze the image of the grating,and thus improve the quality of the image.In this paper,the principle and research status of grating imaging are briefly introduced.The image analysis and recovery in digital image processing and the existing point spread function(PSF)extraction methods are discussed in detail.On this basis,method of remove noise and fitting are improved,a point spread function extraction algorithm for grating imaging is proposed.Then,the image information of the grating under different imaging conditions is collected in the experiment,and the point diffusion function is extracted.The influence of the distance,incident angle,grating space frequency,image distance,wavelength on astigmatism and image quality in grating imaging is obtained by analyzing the relationship between the extracted point spread function and the imaging parameters.The results show that the grating space frequency,incident angle,image distance and wavelength have great influence on the image quality,while the object distance has little effect on the image quality under the same imaging standard.Furthermore,Lucy-Richardson filtering of the astigmatic image is reconstructed according to the extracted point spread function,and the reconstructed image is obtained.The quality evaluation of the reconstructed image is evaluated by the image quality evaluation parameter and MTFA.The results show that the proposed image processing method for analyzing and recovering the grating images,have high feasibility and effectiveness in practice and theory.The research reported in this paper has a reference value for the application of bi-grating imaging system in practice.