Many imaging systems are described by an MTF function. However, MTF is defined rigorously only for linear imaging systems, and the printing process is intrinsically non-linear. However, a spatial attenuation function we call the Printer Transfer Function, PTF, can be defined experimentally, and it behaves much like an MTF. The measurement of the PTF is illustrated for a 300 dpi electrophotographic printer. The PTF is shown to be experimentally independent of the halftone pattern printed, but a scaling factor, r, which is highly dependent on the halftone pattern, is required in order to calculate the noise power spectrum, NPS, of the printed halftone from the NPS of the ideal halftone in the computer.
J. Arney, P. Anderson, P. Mehta, K. Ayer, "The MTF of Printing Systems" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP16), 2000, pp 367 - 369, https://doi.org/10.2352/ISSN.2169-4451.2000.16.1.art00096_1