大面阵小像元光学成像器件加权采样优化技术  

Weighted Sampling Optimization Technology for Large-Format Small-Pixel Optical Imaging Devices

作　　者：庄绪霞[1,2] 阮宁娟 魏久哲[1,2] 贺金平 Zhuang Xuxia;Ruan Ningjuan;Wei Jiuzhe;He Jinping(Beijing Institute of Space Mechanics&Electricity,Beijing 100094,China;Beijing Key Laboratory of Advanced Optical Remote Sensing Technology,Beijing 100094,China)

机构地区：[1]北京空间机电研究所,北京100094 [2]先进光学遥感技术北京市重点实验室,北京100094

出　　处：《光学学报》2024年第22期111-119,共9页Acta Optica Sinica

摘　　要：为实现高像素小像元成像器件在光学成像高效应用,提出一种面向大面阵小像元光学成像器件的加权采样及优化方法。分析大面阵小像元器件加权采样原理,构建加权采样成像质量模型和权重因子优化模型,开展权重因子优化分析,进行加权采样仿真实验与分析评价。研究结果表明,通过加权采样,可以有效提高综合成像质量,5×5像素为一采样单元时,调制传递函数(MTF)最高可以提高1.5倍,信噪比(SNR)最高可以提高5.0倍,MTF×SNR最高可以提高5.2倍以上。本技术研究为大面阵小像元器件新型成像应用提供理论支撑。Objective With the continuous advancement of detector technology,devices with high pixel density and small pixel size are constantly emerging.However,as the pixel size of the detector decreases,the signal-to-noise ratio(SNR)of the detector is reduced,which makes it difficult to meet the SNR requirements for imaging in fields such as space remote sensing.Multi-pixel binning can improve the imaging SNR of small-pixel devices but does not improve the modulation transfer function(MTF)of the system.We aim to achieve the efficient application of large-format small-pixel devices in optical imaging and comprehensively enhance the system’s MTF and SNR by researching a new weighted sampling and optimization method.Methods The weighted sampling and optimization method for large-format small-pixel optical imaging devices is proposed.The weighted sampling method takes several adjacent pixels as a superpixel,and each pixel within the superpixel is assigned a different weight factor.The weight factor is multiplied by the signal of each pixel,and then the signals after weighting are summed up to form the output of the superpixel.Based on the technical principles,a weighted sampling imaging quality is constructed,which includes MTF and SNR.Meanwhile,the image quality is analyzed under different pixel quantities in a superpixel and various weighted factors.By taking MTF×SNR as the optimization target function,the optimization function for the weight factors is constructed.Meanwhile,boundary constraint conditions are set and a global search method is employed.Within the boundary constraints of the variables,the size of the variables is continuously changed for iteration and optimization,thus achieving the optimal setting of the weight factors.The weighted sampling image simulation experiment is conducted,and image MTF tests are performed based on the edge method.Additionally,the SNR is calculated by employing the ratio of the mean and variance of the gray level in the uniform area,and the experiment results are consistent with t

关 键 词：成像系统 大面阵 成像 加权采样 优化 

分 类 号：O436[机械工程—光学工程]