Research On The Image Restoration Of Simple Optical System Imaging

The more complicated the optical system design,the higher the cost and the more difficult to maintain,so it is necessary to use a simple optical imaging system.However,there are serious aberrations in the simple optical system,which leads to the degradation of image quality,blur,distortion and other problems.In this paper,the point spread function model of simple optical system with aberration is established,and a method to solve the problem of image quality degradation is proposed,which is called simple optical system imaging image recovery method based on phase diversity(PD)according to the imaging characteristics of simple optical system.The main contents of this paper are as follows:(1)The imaging characteristics of simple optical system are studied,and several primary aberrations in optical system are analyzed.The relationship among aberration,pupil function,point spread function and optical transfer function is analyzed,and the point spread function model of simple optical system is established.(2)The principle of non-negative support domain recurrent filtering(NAS-RIF),the maximum posterior probability method(MAP)and the phase recovery method(PR)in blind image recovery are studied and their advantages and disadvantages are analyzed.In order to avoid the problems in the above methods,such as uniform image background,small dimension of point spread function and sensitivity of initial input parameters,a simple image recovery method for optical system based on PD method is proposed.The principle of PD method is studied,the mathematical model of PD method is established,the solution of pathological problem in PD method,the relationship between the amount of out-of-focus distortion and the parameters of optical system,and the sampling relationship between pupil plane and image plane of optical system are studied.(3)The subjective evaluation method and objective evaluation method of image quality evaluation are studied,the applicability and limitation of each method are analyzed,and several evaluation indexes of objective evaluation method are analyzed.Using three simple optical systems composed of single lens,two lenses and three lenses,the optical imaging system is built to capture images for image recovery experiments.The quality of image recovery under different simple optical systems is analyzed,the optimal defocusing amount of each optical system is selected,and the image recovery results of different methods are compared,and a single image recovery is carried out according to the obtained point spread function to improve the efficiency of image recovery.The results show that the image quality restored by this method is obviously improved.The image quality of the simple optical system can be close to that of the complex system in a certain range.A single image recovery method can be used to improve the efficiency of image recovery when the structure of the optical system is constant.The method in this paper is of great significance to the simplification of optical system in practical engineering applications.