MTF for Laplacian of a gaussian
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am trying to plot a modulation transfer function of a gaussian from -40 to 40 mm in conjunction with a laplacian of gaussian filter, width = 4 mm and sigma = 1. i have a trouble scaling the MTF for the gaussian and i wasnt sure about how to get the ft for the laplacian of a gaussian. am using abs(fft). does anyone have an experience with MTF for filters?
1 Comment
Star Strider
on 23 Feb 2014
Edited: Star Strider
on 23 Feb 2014
Please post your code, or attach the file to your original question if your code is too long to post. It will help us understand your problem.
This is out of my area of expertise (I’ll search online to see what I come up with), but there are others here who are probably more familiar with it.
Answers (2)
Star Strider
on 23 Feb 2014
The Image Processing Toolbox has functions that can take you from the point spread function to the optical transfer function and back again. See psf2otf for details.
6 Comments
Star Strider
on 27 Feb 2014
Edited: Star Strider
on 1 Mar 2014
I don’t exactly understand what you mean by ‘profile’. I’m hung up on how you project your 3D OTF or MTF to a 2D representation. One paper I found mentions: ‘The spatial-noise amplitude spectrum of the system was independently measured by taking the FFT of the array data (averaged over the rows) when flux was incident on the array at the same average value as for the target image.’ ( ‘Random transparency targets for modulation transfer function measurement in the visible and infrared regions’ ) So it would seem to me that the convention is to take the 3D OTF or MTF, average it over the rows. In MATLAB this would be:
MTF_mean = mean(MTF,2);
if MTF is your 3D representation. You have the result you want.
Is this correct?
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