摘要
为校正长波红外探测器辐射响应非均匀性,抑制非线性和随时间漂移,提出了一种基于分段两点校正法和局部恒定统计的校正方法.首先,对非均匀性噪声建模,利用分段两点校正法进行粗校正;其次,利用绝对偏差中值法剔除异常像素,并迭代累加得到均值图像;最后,对均值图像滤波,求得校正系数矩阵并对图像精校正.搭建了原理样机,进行了两次实验室标定实验和一次外场实验.实验结果表明:本文方法可以将黑体图像标准差从2.75降低至2.26,将外场图像粗糙度从1.47×10-2降低至1.03×10-2.本文方法复杂度低、鲁棒性强、精度高,可以有效去除非均匀性噪声.
To correct the nonuniformity of long-wave infrared detectors and suppress the nonlinearity and time drift,a combined nonuniformity correction method based on piece-wise two-point correction method and local constant statistics was proposed.Firstly,on the basis of the modeling of nonuniform noise,a piece-wise two-point correction method is performed as a coarse correction step.Then,abnormal pixels are kicked out with the median absolute deviation method,and the mean image is calculated through multiple frames in an iterative manner.Finally,the mean image is filtered to obtain the correction matrix for the fine correction step.Two laboratory calibration experiments and one outfield experiment are performed with a principle prototype.Experimental results demonstrate that the standard deviation of the blackbody can be decreased from 2.75 to 2.26,and the roughness of the outfield scenes from 1.47×10-2 to 1.03×10-2.The proposed method has the characteristic of low complexity,strong robustness,and high precision,and is able to reduce nonuniformity noise effectively.
引文
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