光子学报, 2018, 47 (2): 0211001, 网络出版: 2018-01-30
CCD相机调制传递函数增强滤波器设计
CCD Camera MTF Enhancement Filter Design
调制传递函数 低通滤波器 品质因数 CCD相机 带宽 信噪比 Modulation Transfer Function (MTF) Low pass filters Quality factor CCD cameras Bandwidth Signal to Noise Ratio (SNR)
摘要
通过CCD相机成像模型讨论了成像链路各个环节对系统传递函数的影响, 分析了滤波器品质因数的增强效果、品质因数对信噪比的影响, 品质因数对多个像元影响, 分析表明:当相机光学部件及传感器确定之后, 可以通过设置合理的后端滤波电路品质因数来增强系统传递函数; 当滤波器的最佳品质因数设置值为1时, 成像系统在Nyquist空间频率处的传递函数能够提高32%.利用黑白条纹靶进行相机传递函数测试及信噪比测试, 试验结果表明, 调制传递函数增强滤波器在品质因数为1时可提高CCD成像相机的成像性能, 提高传递函数30%; 电路噪声抑制能力与通带内最平坦滤波器相当.
Abstract
By the discussion of the impact to system MTF by each link in image chains based on the camera imaging model, the enhancement effect of filter quality factor, the impact to Signal to Noise Ratio (SNR), simulation results of the impact of quality factor on multiple pixels were analyzed. The analysis show that the appropriate filter quality factor could enhance the system MTF after the optical design is done and the sensor is confirmed. If the optimum quality factor setting value of the filter is 1, the system MTF at the Nyquist spatial frequency can be increased by 32%. The test results show that MTF enhancement filter can improve the system imaging performance when the quality factor is 1, and the noise suppression capability is comparable to that of the maximally flat filter in passband.
张健, 樊养余, 朱波, 许哲, 赵燕. CCD相机调制传递函数增强滤波器设计[J]. 光子学报, 2018, 47(2): 0211001. ZHANG Jian, FAN Yangyu, ZHU Bo, XU Zhe, ZHAO Yan. CCD Camera MTF Enhancement Filter Design[J]. ACTA PHOTONICA SINICA, 2018, 47(2): 0211001.