Droege R T, Rzeszotarski M S
Med Phys. 1985 Nov-Dec;12(6):721-5. doi: 10.1118/1.595654.
The variance derived from the images of cyclic bar patterns can be used to determine the modulation transfer function (MTF) of an imaging system. Unlike most MTF methods, it is applicable even when the imaging system undersamples the test object and generates aliasing errors. The validity of the variance method in the presence of aliasing is established theoretically and by computer simulation.
从周期性条形图案图像中导出的方差可用于确定成像系统的调制传递函数（MTF）。与大多数MTF方法不同，即使成像系统对测试对象进行欠采样并产生混叠误差，该方法也适用。方差方法在存在混叠情况下的有效性已通过理论和计算机模拟得到证实。
