Scattered light imaging through complex turbid media has significant applications in biomedical and optical research.For the past decade,various approaches have been proposed for rapidly reconstructing fullcolor,depth...Scattered light imaging through complex turbid media has significant applications in biomedical and optical research.For the past decade,various approaches have been proposed for rapidly reconstructing fullcolor,depth-extended images by introducing point spread functions(PSFs).However,because most of these methods consider memory effects(MEs),the PSFs have angular shift invariance over certain ranges of angles.This assumption is valid for only thin turbid media and hinders broader applications of these technologies in thick media.Furthermore,the time-variant characteristics of scattering media determine that the PSF acquisition and image reconstruction times must be less than the speckle decorrelation time,which is usually difficult to achieve.We demonstrate that image reconstruction methods can be applied to timevariant thick turbid media.Using the time-variant characteristics,the PSFs in dynamic turbid media within certain time intervals are recorded,and ergodic scattering regimes are achieved and combined as ensemble point spread functions(ePSFs).The ePSF traverses shift-invariant regions in the turbid media and retrieves objects beyond the ME.Furthermore,our theory and experimental results verify that our approach is applicable to thick turbid media with thickness of 1 cm at visible incident wavelengths.展开更多
Recording and identifying faint objects through atmospheric scattering media by an optical system are fundamentally interesting and technologically important.We introduce a comprehensive model that incorporates contri...Recording and identifying faint objects through atmospheric scattering media by an optical system are fundamentally interesting and technologically important.We introduce a comprehensive model that incorporates contributions from target characteristics,atmospheric effects,imaging systems,digital processing,and visual perception to assess the ultimate perceptible limit of geometrical imaging,specifically the angular resolution at the boundary of visible distance.The model allows us to reevaluate the effectiveness of conventional imaging recording,processing,and perception and to analyze the limiting factors that constrain image recognition capabilities in atmospheric media.The simulations were compared with the experimental results measured in a fog chamber and outdoor settings.The results reveal good general agreement between analysis and experiment,pointing out the way to harnessing the physical limit for optical imaging in scattering media.An immediate application of the study is the extension of the image range by an amount of 1.2 times with noise reduction via multiframe averaging,hence greatly enhancing the capability of optical imaging in the atmosphere.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61991452 and 12074444)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030009)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(Grant No.2020A1515011184)the Guangzhou Basic and Applied Basic Research Foundation(Grant No.202102020987).
文摘Scattered light imaging through complex turbid media has significant applications in biomedical and optical research.For the past decade,various approaches have been proposed for rapidly reconstructing fullcolor,depth-extended images by introducing point spread functions(PSFs).However,because most of these methods consider memory effects(MEs),the PSFs have angular shift invariance over certain ranges of angles.This assumption is valid for only thin turbid media and hinders broader applications of these technologies in thick media.Furthermore,the time-variant characteristics of scattering media determine that the PSF acquisition and image reconstruction times must be less than the speckle decorrelation time,which is usually difficult to achieve.We demonstrate that image reconstruction methods can be applied to timevariant thick turbid media.Using the time-variant characteristics,the PSFs in dynamic turbid media within certain time intervals are recorded,and ergodic scattering regimes are achieved and combined as ensemble point spread functions(ePSFs).The ePSF traverses shift-invariant regions in the turbid media and retrieves objects beyond the ME.Furthermore,our theory and experimental results verify that our approach is applicable to thick turbid media with thickness of 1 cm at visible incident wavelengths.
基金supported by the National Natural Science Foundation of China(Grant Nos.61991452 and 12074444)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030009)the National Key Research and Development Program of China(Grant Nos.2022YFA1404300 and 2020YFC2007102).
文摘Recording and identifying faint objects through atmospheric scattering media by an optical system are fundamentally interesting and technologically important.We introduce a comprehensive model that incorporates contributions from target characteristics,atmospheric effects,imaging systems,digital processing,and visual perception to assess the ultimate perceptible limit of geometrical imaging,specifically the angular resolution at the boundary of visible distance.The model allows us to reevaluate the effectiveness of conventional imaging recording,processing,and perception and to analyze the limiting factors that constrain image recognition capabilities in atmospheric media.The simulations were compared with the experimental results measured in a fog chamber and outdoor settings.The results reveal good general agreement between analysis and experiment,pointing out the way to harnessing the physical limit for optical imaging in scattering media.An immediate application of the study is the extension of the image range by an amount of 1.2 times with noise reduction via multiframe averaging,hence greatly enhancing the capability of optical imaging in the atmosphere.
