Monotone spline regression for accurate MTF measurement at low frequencies.
Monotone spline regression for accurate MTF measurement at low frequencies.
复制标题
DOI：
10.1364/oe.22.022446
复制
发表时间：
2014-09
期刊：
影响因子：
3.8
通讯作者：
Zhong-xing Zhou;F. Gao;Huijuan Zhao;Lixin Zhang;L. Ren;Zheng Li;Muhammad U. Ghani;Hong Liu
中科院分区：
文献类型：
--
作者：
Zhong-xing Zhou;F. Gao;Huijuan Zhao;Lixin Zhang;L. Ren;Zheng Li;Muhammad U. Ghani;Hong Liu
射线照相系统的调制传递函数（MTF）通常由使用窄缝的系统的线扩展函数（LSF）来评估。传统的狭缝方法需要LSF尾部近似，这是通过指数外推超过峰值的1%的LSF尾部来实现的。然而，从外推法估计的在低频处的MTF可能不反映系统的真实性能。在本研究中，我们发展了一种单调样条回归技术，以提高低频MTF估计的精度。该技术基于系统响应的基本物理原理。这种技术的优点与模拟的例子，其中真正的MTF是已知的。这种测量技术的应用也被证明。
The modulation transfer function (MTF) of radiographic systems is frequently evaluated by the system's line spread function (LSF) using narrow slits. The conventional slit method requires LSF tail approximation, which is achieved by exponentially extrapolating the LSF tails beyond 1% of peak value. However, the estimated MTF at low frequencies from extrapolation may not reflect the true performance of the system. In this study, a monotone spline regression technique for LSF tail approximation is developed to improve the accuracy of MTF estimation at low frequencies. This technique is based on the underlying physical principles of the system response. The advantages of this technique are demonstrated with simulated examples of which the true MTFs are known. The application of this measurement technique is also demonstrated.