Research On Imaging Through Scattering Medium Based On Statistical Average Fourier Transformation

Light is an important vehicle for people to observe and obtain image information about objects,and is an important way to perceive the environment.When the imaging light path is ideal,light is usually transmitted in free space in a straight line and a direct mapping relationship between the object and the image is met,but in the natural environment there are often obstacles between the observer and the observed object.For example,when a scattering medium such as particles or haze is present in the imaging optical path,light scattering occurs and the incident light wavefront is destroyed,resulting in the photoelectric imaging system not being able to image properly under these conditions.In order to solve the problem of not being able to image the observed object clearly in the presence of scattering media,a number of imaging methods through scattering media have been developed.This paper focuses on the use of statistical averaging and Fourier transform methods for imaging through scattering media,by rotating the scattering media to perform a scattering averaging operation,changing the exposure time of the camera,replacing the ensemble average with the time average of the scattering field,thus eliminating the random phase introduced by the scattering media,and recording the object information by means of the interference between the object light and the reference light.The object information can be recovered by simply Fourier transforming of the interferometric scatter image.The method is simple,compact,fast and inexpensive,and does not require phase correction,a priori knowledge acquisition or complex image processing.A statistical averaging and Fourier transform imaging system through the scattering medium is built using a single rotating scattering medium.The effect of the ground glass rotation speed and CCD exposure time on the Peak signal-to-Noise ratio of the reconstructed image is investigated.The experimental results show that at a rotation speed of 1.5 rpm and an exposure time of 800 ms,the imaging system can resolve the third element of group four of the resolution plate.However,it is rare to have a rotating scattering medium in practical imaging scenarios,and for this reason,a combination of dynamic and static dual scattering medium imaging is used,thus extending the application of the method.The results showed that the method was able to image the target object clearly,although the imaging quality was degraded compared to that through a single rotating scattering medium.The effect of the average scattering size on the quality of the reconstructed image was then investigated,and the results showed that the larger the average scattering size,the higher the quality of the reconstructed image under the available experimental conditions.When the mean scatter size was 368 μm,the structural similarity was 0.3124.Finally,the contrast of the reconstructed image was effectively improved by filtering out the central bright spot through high-pass filtering.Although the use of reference light in the experimental optical path is required to assist the imaging,the advantages of fast and simple reconstruction allow the method to perform real-time imaging and provide a new idea for imaging through scattering media.