Measurement of the presampling modulation transfer function of film digitizers using a curve fitting technique.
Measurement of the presampling modulation transfer function of film digitizers using a curve fitting technique.
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DOI：
10.1118/1.596463
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发表时间：
1990-11
期刊：
影响因子：
3.8
通讯作者：
F. Yin;M. Giger;K. Doi
中科院分区：
文献类型：
--
作者：
F. Yin;M. Giger;K. Doi
本文提出了一种结合狭缝像的曲线拟合技术，用于测量胶片数字化仪的前置调制传递函数（MTF）。噪声线扩展函数（LSF）从一个角度狭缝图像获得的拟合使用两个函数的组合，通过非线性最小二乘拟合技术。每个LSF的模型函数中的参数通过最小化残差均方根（RMS）获得，然后在所有LSF拟合上取平均值。得到的分析函数代表连续预采样LSF。我们发现，高斯函数和指数函数的组合与使用胶片数字化仪获得的LSF具有良好的拟合。对模型函数进行相应的解析傅里叶变换，得到了无奈奎斯特频率限制的预调制传递函数。使用这种方法的空间分辨率特性的测量进行了两个激光扫描仪和一个光学鼓扫描仪。
A curve fitting technique combined with an angulated slit image has been developed for the measurement of the presampling modulation transfer function (MTF) of film digitizers. The noisy line spread functions (LSFs) acquired from an angulated slit image are fitted using a combination of two functions by means of a nonlinear least-square fitting technique. The parameters in the model function for each LSF are obtained by minimizing the residual root mean square (RMS), and then averaged over all the LSF fittings. The resulting analytical function is representative of the continuous presampled LSF. We have found that a combination of Gaussian and exponential functions provides a good fit to the LSFs obtained with film digitizers. The corresponding analytical Fourier transformation of the model function yields the presampling MTF, without Nyquist frequency limitation. Measurements of spatial resolution properties using this method were performed for two laser scanners and an optical drum scanner.