Any notes or examples available on calculating the modulation transfer function of an imaging system in matlab

Hi everyone,

Just wondering if anyone has experience of using matlab to calculate the modulation transfer function of an imaging system? I've been tasked with doing this instead of my usual lab work as I'm currently working at home and don't really know where to start. Parameters to change in the model should be lens width and source extent. I want to start with a completely incoherent source with cross-spectral density

As I understand it, the MTF of the system is the ratio of the visibility before and after the optics:

and I have been given the equation

where

and is the impulse response. I'm really struggling to see how I can turn this into something I can code in Matlab. I've been asked to calculate the MTF of this system for different source extent and lens width but I don't even know how these parameters fit into the model. I am told that this is just an LED shining through a lens onto a diffraction grating which has a periodic structure but I'm currently unable to relate the physical picture to parameters I can model. Can anyone help?

edited by guillaume: Fix to latex

Answer 1

[Guillaume]

If I remember correctly, there is matlab code that comes with the iso standard on MTF (ISO 15529:2010).

I can't remember where I got it, but a search for sfrmat shows that it's at least available here

Matlab also has the functions otf2psf and psf2otf which are components of the MTF.

" the MTF of the system is the ratio of the visibility before and after the optics"

I wouldn't describe it like that. It's more the ability of your optical system to transmit contrast for a given object size, typically given as lines (or cycles) per mm.