Signal transfer function
![The red line is the SiTF. As can be seen, a line is fitted to the linear portion of the signal output versus signal input of an infrared sensor.](/Images/godic/202502/11/Example_graph_of_SiTF0531.jpeg")
![Half moon target – on the left the image of the background region and on the right an image of the signal region. Using specialized software, an operator arbitrarily defines an area of evaluation in both regions to be used in determining the signal transfer function.](/Images/godic/202502/11/SiTF_Half_Moon_Target0531.jpg")
The signal transfer function (SiTF) is a measure of the signal output versus the signal input of a system such as an infrared system or sensor. There are many general applications of the SiTF. Specifically, in the field of image analysis, it gives a measure of the noise of an imaging system, and thus yields one assessment of its performance.