Analysis And Application Of Fast Single-pixel Imaging With Photodetectors Array

Image is the major way to acquire information and discover the world for people.The traditional imaging method based on optoelectronic imaging has been applied to all aspects of people's life.As a method of computational imaging,single-pixel imaging has been developed rapidly in recent years.Single-pixel imaging has the characteristics of wide imaging spectrum,imaging in weak light intensity and imaging objects out of imaging field.Different from the traditional optoelectronic imaging method,single-pixel imaging is an imaging method for reconstructing an image by processing the correlations between the scene and a series of illumination patterns,which means that the optical imaging equipment of traditional optoelectronic imaging methods is no longer relied.In order to realize the principle analysis and application in array computational imaging and fast single-pixel imaging,this paper studies the principle and application of single-pixel imaging.The main contents of this paper are as follows:(1)The development history from traditional imaging to computational imaging is summarized,and the principle of traditional imaging is analyzed in this paper.The physical principle of single-pixel imaging is analyzed based on the coherence analysis of light field.The principle and characteristics of different types of single-pixel imaging methods are summarized and analyzed in the paper.(2)Based on the analysis of the principle of single-pixel imaging,the hardware platform and software program of single-pixel imaging is designed in the paper.The hardware devices and relevant programs are selected and written based on the analysis above.Through simulation and test verification,the experimental platform of single-pixel imaging is built eventually.(3)A two-step phase shift Fourier single-pixel imaging method is proposed to reduce the number of illumination patterns needed in current single-pixel imaging methods.The Fourier spectrum of the target image is obtained by the difference calculation method based on the base pattern introduced.This method can reduce the number of illumination patterns effectively to shorten the time single-pixel imaging needed in condition of no image quality loss theoretically.(4)A method of using single-pixel imaging to remove the light interference in the imaging process is studied and introduced to improve the accuracy of optical character recognition.This paper uses the difference calculation of single-pixel imaging to eliminate the interference light in the imaging process without using the image post-processing method.The single-pixel imaging methods can eliminate part of the interference light completely,which improves the accuracy of optical character recognition greatly.(5)A single view virtual coaxial shadowless imaging structure is designed to reduce the shadow area in the reconstructed image effectively.In the process of stereo target imaging,shadow often appears in the reconstructed image,which leads to the loss of image information.A beam splitter is used to change the optical path to form a virtual coaxial structure to eliminate the shadow of the reconstructed image.The method proposed in this paper only uses a single view of a single detector to eliminate the shadow of the image in the process of imaging,which improves the amount of information of the image acquired by single-pixel imaging effectively.(6)A bionic planar compound eye with large field of view is developed,and on this basis,the field of view and the image quality improvement of array single-pixel imaging are studied in the paper.Based on the research of biological compound eye,this paper proposes an array planar compound eye design,which expands the imaging field of view effectively.Parabolic mirror,free-form mirror and microlens array are designed and manufactured,and the prototype of planar compound eye array is built eventually.The image information of large field of view scene is obtained by fusing multi-channel image information.On the basis of the planar compound eye,the field of view of the active and passive array single-pixel imaging are studied in the paper.Based on the prototype platform of planar compound eye array,this paper uses multiple optical fibers and multiple photodetectors to form an array single-pixel imaging system,and obtains multiple image information of the target simultaneously.The quality of the reconstructed image is effectively improved by processing multiple target images obtained by the array single-pixel imaging system.