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• MADA
• MAI
• MC
• mesotrophic
• microtubule
• MTF
  • definition
  • measurement

MTF - modulation transfer function.

One of the key characteristics of image transfer in turbid media (and of the imaging system), MTF is the spatial frequency-dependent contrast (modulation) in the image of an object relative to that in the object reflectance map itself (for example, Boreman GD 2001b, Wyatt CL 1991, pp. 196-213). MTF is the magnitude of a more comprehensive characteristics of optical image transfer, the optical transfer function (OTF), which is a product of the MTF and a complex-valued phase transfer function (for example, Boreman GD 2001c, see also Point spread function vs. optical transfer and modulation transfer functions).

As its definition implies, MTF of an imaging process can be expressed by the product of the MTF of the imaging process steps (for example, imaging through a layer of turbid medium) and of the imaging system itself. The latter can be further decomposed into a product of MTFs of the imaging system components, such as the lens, and the image detector.

In imaging through a turbid medium, the medium has frequently the dominant role determining the overall MTF, unlike in imaging through "transparent" media such as clear atmosphere at short distances, where the imaging system properties typically dominate the overall MTF. The turbid medium MTF is determined by scattering of light by the medium. Hence, unlike the imaging system MTF, the MTF of a turbid medium depends on the distance through which the image is transferred (see modulation transfer function, of turbid medium, distance dependence).See also MTF measurement.

[MJ]