Multi-band Polarization Imaging And Image Processing In Sea Fog Environment

With the deepened altitude of research in the marine field today,marine scene detection has become a popular area of concern and research domestically and internationally.The water vapor in the atmosphere which closes to the sea surface,also known as sea fog,is condensed to form sea salt aerosols,causing wider scattering of light waves in chaotic media,and the energy of light waves is became greatly attenuated to a certain extent.As a result,the scene information is severely weakened by the sea fog during the imaging process,resulting in unsatisfactory imaging results.At the current standing point,the information contained in the images collected by traditional intensity cameras has low application value,and the needs of researchers can no longer be met.Therefore,obtaining images with more information will become a problem to solve in this research field.After analyzing the reasons for the degradation of sea fog imaging,this article focus on the research of polarization imaging to obtain a more effective polarization image.The main research contents of this article are divided into the following two aspects:(1)In the special environment of sea fog,little research has been done on polarization imaging.In view of the lack of sharpness of traditional intensity camera imaging,based on the theory of polarization optics,this article uses the principle of liquid crystal phase retarder for polarization imaging.An optical imaging platform has been set up in an outdoor environment to perform sea fog imaging experiments.By processing the corresponding image containing the polarization parameter can be calculated and the polarization image could be analyzed.The experimental results show that when the imaging of the sea fog environment is not clear,using this method of imaging can obtain data of traditional intensity images,and multidimensional polarization information.The above result highlights the advantages of targeting image under special backgrounds,thereby improving the image use value.(2)In this paper,multi band polarization imaging method is proposed to solve the problem of single research band.Using the medium of sea fog concentration levels characterized by optical thickness,the elevation angle of the sun,multiple bands as variables,from the aspects of contrast,information entropy,and polarization,objectively analyze the advantages of polarization imaging in a sea fog environment.After that,in order to compare the imaging differences between sea fog and non sea fog environment,an artificial simulation system is established in this paper.Through the self-made sea fog simulation device to carry out indoor comparative polarization imaging experiment,it can provide accurate data and technical support for multiband polarization imaging in sea fog environment.The results show that as the optical thickness of the sea fog increases,the polarized light is weakened in the medium,making the image effect blurred.Compared with the intensity image,the quality of the polarized image has improved,and the outline of the target object is more acute,and the edges are sharper.The polarization imaging effect at 670 nm is the best.The contrast of the polarization image is affected by the time period and sun azimuth,but it is roughly the same as the trend of the light intensity information polyline.This lays a good foundation for the field survey of severe sea fog weather and civil activities.