串音使得焦平面输出信号的对比度降低，进而影响系统的调制传递函数(MTF)。随着器件的发展，用MTF来评价器件越来越受到重视；从民用领域的趋势看，MTF将逐步取代传统的串音、极限分辨率等参数。这就使得现阶段搭建串音专用测量设备处于进退两难的地位。考虑到串音和MTF间的密切联系，从串音的定义和传统测量方法出发，分析了串音和MTF间存在的定量关系，指出在Nyquist频率处串音影响下的总体MTF与无串音时的总体MTF存在一最大差值；据此得出了从实测红外焦平面MTF曲线计算百分比串音值的一种新方法。

Crosstalk will lower down the modulation of the output signal of focal plane arrays (FPA), and then degrade the system′s overall modulation transfer function (MTF). With the development of photoelectric devices, using MTF to evaluate the performances of photoelectric devices is becoming more and more popular. Seen from the trend in civil imaging field, MTF will gradually replace typical parameters such as crosstalk and extreme resolution in evaluation of photoelectric devices. And this makes it a dilemma to decide whether to build a dedicated equipment for crosstalk measurement or not. Considering the relation between crosstalk and MTF, their correlation is analyzed qualitatively, starting from the definition and typical measurement method of crosstalk. It is pointed out that the difference between system′s overall MTF with and without crosstalk maximizes at the Nyquist frequency. Based on this, a new method of calculating percentage crosstalk from measured MTF curves of infrared FPAs is got.