一种基于针孔像分析的光学系统调制传递函数测量的自适应背景校正方法

A New Adaptive Background Correction Method Based on Pinhole Image Analysis in Optical System Modulation Transfer Function Measurement

提出了一种基于针孔像分析的光学系统调制传递函数(MTF)测量自适应背景校正的方法。由CCD显微系统采集针孔目标经被测光学系统成像后的针孔像,计算线扩展函数,并对其进行自适应背景校正,获取MTF。该方法与传统方法相比,消除了周围环境光照变化的影响,提高了测量精度。为验证所提方法的有效性,对标准镜头进行MTF测试,将测试结果与理论设计值比对,测试结果差异极大值为0.01;与美国Optikos公司的测试结果比对,测试结果差异极大值为0.015;对大像差光学系统的轴上和轴外进行MTF测试,并将测试结果与美国Optikos公司测试结果比对,测试结果差异极大值为0.013。实验表明,该方法可满足对不同像差光学系统轴上和轴外MTF的测量。

A new adaptive background correction method based on pinhole image analysis in optical system modulation transfer function （MTF） measurement is proposed. The pinhole image is got from the CCD, and the line spread function is computed from it. The MTF is got from the adaptive background correction to the line spread function. Compared with the traditional background correction method, it is unrelated to the change of ambience illumination, and the measurement accuracy is improved. Standard lens and aberrated lens are tested to prove the validity of the adaptive background method. The maximum difference between the test results of standard lens and the academic results is 0.01. Compared with Optikos MTF testing results, the maximum difference is 0.015. The maximum difference between test results of aberrated lens and Optikos MTF testing results is 0.013. The test results show that the adaptive background correction method is practical to the MTF tests of most optical lenses.