【作者】 王腾飞； 傅雨田；

【Author】 WANG Teng-fei;FU Yu-tian;Key Laboratory of Infrared System Detection and Imaging Technology,Chinese Academy of Science;Shanghai Institute of Technical Physics,Chinese Academy of Sciences;University of Chinese Academy of Sciences;

【机构】 中国科学院红外探测与成像技术重点实验室； 中国科学院上海技术物理研究所工程九室；

【摘要】 光场成像是一种独特的成像技术,可通过记录场景光线的位置与方向信息,数字重聚焦成像。红外光场相机与传统光场相机不同,需要在光场成像的同时,考虑背景辐射和非均匀性对光场成像的影响。本文完成了对红外光场相机的系统设计,对光场相机的原理和红外成像的特点进行了理论分析,推导了系统输出信号重聚焦计算的表达式,建立了红外光场相机成像模型,模拟了光场成像的过程。通过倾斜刃边法计算了调制传递函数曲线,以此作为评价光场成像像质的依据。模拟了目标辐射与背景辐射在有无微透镜阵列两种情况下的探测器能量分布情况,对比分析了微透镜阵列对目标辐射和背景辐射的衰减作用。在输出信号中引入了以正态分布描述的非均匀性和背景辐射因素,分析了其对红外光场成像的影响。光场成像的重聚焦算法使得非均匀性会在重聚焦成像时平均化,减弱了非均匀性对红外光场成像的影响。通过调节输出信号的直流偏置,可以减弱非均匀性平均化后的背景辐射对红外光场成像的影响。更多还原

【Abstract】 Light field imaging is a unique imaging technique.Photographs focused at different depths are computed by recording position and direction information of the scene rays.Unlike conventional light field cameras,the effect of background radiation and non-uniformity on light field imaging is considered while infrared light field cameras image the scene.In this paper,the infrared light field camera is designed.Mechanism of light field cameras and characteristics of infrared imaging are analyzed theoretically.The expressions of system output signal with refocusing are derived.The infrared light field camera imaging model is established and the process of light field imaging is simulated.The slanted-edge method is used to calculate the modulation transfer function curve which is considered as a basis for the evaluation of image quality of the light field camera.In the presence or absence of microlens array,energy distribution of the target radiation and the background radiation on the sensor are simulated.The attenuation of target radiation and background radiation by microlens arrays are analyzed and compared.Nonuniformity described by the normal distribution and background radiation are introduced into the output signal,and the influence on the infrared light field imaging is analyzed.The refocusing algorithm of light field imaging makes the nonuniformity averaged during refocusing imaging,which reduces the influence of non-uniformity on infrared light field imaging.When nonuniformity is averaged,the effect of background radiation on infrared light field imaging can be decreased by adjusting the DC offset of the output signal.更多还原