Research On Digital Holographic Super-resolution Technology Based On Multi-frame Image Reconstruction

The trend of miniaturization in the industrial field has made micro-optical components widely used.Digital holography is an important optical detection method,which is characterized by non-destructive,fast,non-invasive.However,when the parameters of micro-optical components are detected,there are still problems such as low imaging resolution and unsatisfactory image quality.Therefore,how to effectively improve the resolution of digital holographic imaging systems and achieve accurate measurement of micro-optical elements has become a hot spot of current research.Aiming at the problem of digital holographic super-resolution imaging,in this dissertation,the research of digital holographic super-resolution technology based on multi-frame image reconstruction is carried out.Its main contents include the following:Firstly,the theoretical basis of digital holographic super-resolution technology is studied.The basic principles include the recording and reproduction of digital holography,the phase reconstruction of holograms,and multi-frame image super-resolution reconstruction algorithms.At the same time,introduced three image quality evaluation indicators,which provides a theoretical basis for subsequent simulation analysis and experimental research.Secondly,the digital holographic micro super-resolution experimental system is designed and constructed.The design of the experimental system includes the digital holographic interference optical system and the image super-resolution reconstruction structure.According to the requirements of the system,appropriate experimental devices are selected,the system is completed,and a hologram sequence with sub-pixel displacement is collected.Finally,the experimental research of hologram reconstruction is carried out.In the experimental study of the reproduction algorithm,the experimental results compare with the data measured by the white light interferometer,and show that the angular spectrum method has better flexibility and higher reconstruction accuracy,and the diameter residual and height residual are 0.65?m and 0.08?m,respectively.In the applicability of multi-frame image super-resolution reconstruction algorithm in digital holography,the cameraman image and USAF1951 resolution target image were used for simulation.The simulation results show that the resolution is improved from 6.20?m to 4.92?m.Using the USAF1951 resolution target hologram and microlens array hologram,the effectiveness of three super-resolution reconstruction algorithms,such as non-uniform interpolation method,convex set projection method and maximum posterior probability method,in hologram reconstruction is verified from2 D and 3D reconstruction,respectively.The experimental results show that the reconstruction results of the reference hologram arecompared with the reconstruction results of low-resolution hologram obtained from experiment and the super-resolution reconstruction hologram,respectively,and the PV and RMS values of the latter's residuals are reduced compared with the former to varying degrees.Among them,the reconstructed hologram based on the convex set projection method has the highest 3D reconstruction accuracy,and the PV and RMS values are reduced by 60.74% and 43.03%,respectively.It shows that the 3D reconstruction result of super-resolution hologram is closer to the reference value,which proves that this method can improve the image resolution of hologram and effectively improve the measurement accuracy of digital holography.