摘要
为了定量研究线阵电荷耦合器件(CCD)错位成像技术的不同错位模式的调制传递函数(MTF),提出了基于MTF的评估方法,避免了以往方法表征图像质量不全面等缺点。推导了线阵CCD错位成像模式的MTF。分析表明,相比于线阵CCD的传统成像模式,利用多个线阵CCD实现错位1/2、1/3、1/4个CCD像元的错位成像模式的极限分辨率分别提高了86.2%、88.78%、89.54%,归一化空间频率0.5处MTF值分别提高了0.1679(41.43%)、0.2026(49.99%)、0.2151(53.07%),空间频率范围(0,0.5)内调制传递函数面积(MTFA)分别提高了10.09%、12.08%、12.77%。在Matlab平台上进行了仿真实验,并用灰度平均梯度和拉普拉斯能量从客观上评估了几种错位成像模式的图像质量,实验结果验证了MTF定量分析的有效性。提出的方法为后期星载遥感相机错位成像系统的设计提供了参考。
In order to evaluate the modulation transfer function （MTF） of different subpixel imaging modes of spaceborne linear charge-coupled device （CCD）, a quantitative assessment method based on MTF which can better characterize image quality is proposed. The MTF of subpixel imaging modes of linear CCD is derived. Compared with conventional imaging mode by a single linear CCD, analysis shows that, theoretical limiting resolution values of 1/2, 1/3, 1/4 CCD-pixels staggered subpixel imaging modes by simultaneously using multiple uniform linear CeDs are improved by 86.2%, 88. 78%, 89. 54%, respectively, MTF values at normalized spatial frequency of 0. 5 are increased by 0. 1679 （41.43%）, 0.2026 （49.99%）, 0.2151 （53.07%） respectively, and modulation transfer function areas （MTFAs） in the normalized spatial frequency range of （0, 0.5） are enhanced by 10.09 %, 12.08 %, 12.77%, respectively. Simulation experiment on Matlab platform is performed. Gray mean gradient （GMG） and energy of Laplacian （EOL） are utilized to evaluate the image quality performance of three subpixel imaging modes objectively and the results demonstrate the validity of this method. The proposed method has some reference value to the design of linear CCD subpixel imaging system in remote sensing.
出处
《激光与光电子学进展》
CSCD
北大核心
2013年第12期87-94,共8页
Laser & Optoelectronics Progress
基金
国家863计划(86325113B)
关键词
成像系统
遥感
线阵电荷耦合器件错位成像
调制传递函数
极限分辨率
灰度平均梯度
拉普拉斯能量
imaging systems
remote sensing~ linear charge-coupled device subpixel imaging
modulation transferfunction~ limiting resolution
gray mean gradient
energy of Laplacian
