Research Of Recovering The Gray Image Based On Polarimetric In Complex Underwater Imaging Environment

Polarization imaging and polarization measurement technology is a new kind of optical detection technology which compares with traditional optical imaging and measurement technology.This technology combines polarization measurement with image processing.By measuring the polarization state(Stokes vector)of the object light wave or the modulation of the polarization state(Mueller matrix)of the object,the problem that traditional optics cannot solve in the field of target detection and recognition can be effectively solved,and obtains the high contrast detection image.In this paper,we mainly study the recovery technology of polarized images in complex underwater environment to improve the quality and effect of images.In the first part of this paper,the research background and significance of this subject are expounded from the influence of various complex environments on human eyes,machine vision,target detection and recognition.Then,this part introduces the research progress and shortcomings of image recovery methods in scattering environment at home and abroad,and briefly summarizes two main image recovery methods,polarization difference dehazing and the research of underwater circularly polarized light in strong scattering environment.Finally,the main contents of this paper are summarized.In the second part of this paper,the analysis method of polarized light is discussed.Based on the basic theory of polarized optics,the polarization phenomena and basic physical concepts of light are introduced.On this basis,polarization imaging systems with different structures and measurement methods of polarization parameters are analyzed and discussed.In the third part,the traditional physical model of polarization dehazing is discussed firstly,and the limitations of the existing methods of underwater image recovery based on polarization imaging are summarized.Considering the different polarization characteristics of the detected object,a polarization image recovery method based on underwater transmittance correction is proposed to recovery the reflected light of the object in the underwater scattering medium environment.In the fourth part,the non-uniform distribution of the degree of polarization of the scattered light in the whole imaging scene caused by the active illumination is discussed.A method of polarization image recovery in scattering environment is proposed.Considering and utilizing the influence of the nonuniformity of polarized light field on the spatial distribution of backscattered light,the global distribution of backscattered light polarization is obtained by fitting the three-dimensional polarization of backscattered light in the background region.Then we can get the recovery image after further calculation.In the fifth part,we discuss that circularly polarized light has better "polarization memory" ability than linearly polarized light in strong scattering medium environment.Based on the "polarization memory" ability of circularly polarized light,a combined image recovery method based on circularly polarized light and linearly polarized light is proposed to further improve the quality of polarized image recovery in strong scattering media environment.