Study On The Method For The Super Resolution Restoration Of Single Image Based On The Principle Of Optical Imaging

Aiming at the high demand of image super-resolution restoration technology in the various fields,considering the limitations of common restoration methods,the principle and mechanism of optical imaging system are analyzed,based on which the idea and method of image super resolution restoration and image quality improvement are discussed by stepwise theoretical derivation and simulation.The main contents are as follows:1.Based on the extensive research on the history and research status of image super-resolution restoration,the limitation of the current recovery methods is pointed out: The main idea of restoration is that the original low-resolution images are mathematically processed to obtain high-resolution restoration images,rarely considering how to combine the optical system imaging process to optimize the high-resolution images.2.The basic mechanism of optical imaging and other related aspects are studied.Starting from the mechanism of optical imaging process,the phase transform and Fourier transform of thin lens in the optical system are discussed.Then the effect of the lens aperture on the spatial frequency is deeply discussed and the complex amplitude expression considering the lens aperture effect is calculated.The influence of object distance on Fourier transform is also discussed.Moreover,the theory of transfer function of optical system is described in detail,which is the basis for the study of optical imaging process by using transfer function.Finally,this thesis discusses the principle that objects are composed of different spatial frequency information,and introduces the method of processing the image in the frequency domain.3.New ideas and methods for the image super-resolution are discussed.Based on the principles of the optical imaging system,we simulated and analyzed the imaging of one-dimensional rectangular grating.This gives us the idea of recovering the high-frequency information from the frequency domain by bandwidth extrapolation,so as to realize the image super-resolution restoration.The idea can be generalized to any object due to its mathematic basis.In addition,we also propose the idea of super-resolution with prior information.4.Discussion of image quality improvement method based on wavefront coding techniques.Aiming at the problem that the depth of field of traditional optical imaging system is limited,the image quality is degraded and the resolution is reduced when defocusing,the imaging system is optimized by wavefront coding techniques.The principle that the wavefront coding imaging can extend the imaging depth of field is explained and verified by simulation.Aiming at the spatial frequency cutoff problem caused by the detector pixel size limitation,the super-resolution image restoration method combined with image magnification is adopted to further improve the performance of the imaging system.5.Discussion on image quality improvement method based on range gating techniques.In view of the application of super-resolution restoration technology under poor weather conditions,the image quality improvement method based on distance gating technique was discussed.Through theoretical analysis,simulation and experiments,it was verified that this technology can effectively elimination the impact of atmospheric backscattering,and improve the SNR and quality of imaging.The research of this paper fully combines the principle mechanism of optical system imaging process,and proposes a new idea and method for image super resolution restoration,and image quality improvement methods based on wavefront coding and gated imaging technology,which has a certain significance for research in this field.