| Category: |
Image Processing |
| Author: |
|
| Description: |
Some example functions/code which show how to do FFT manipulation. Please use/develop/expand and correct these examples at will.
To use this script, have an image with periodic information in it foremost. Something like a HRTEM image will do fine. The image must be square and have dimensions an integral power of 2 eg 512 x 512, 1024 x 1024 etc.
The script shows how to :
Calculate the FFT of an image
Calculate the inverse FFT of an FFT
Create a Butterworth filter to use for high frequency (noise) filtering
Apply the Butterworth filter to a FFT
Carry out the inverse FFT of the above to show the effect of filtering
Extract the real component of a complex image
Extract the imaginary component of a complex image
Compute the magnitude component of the FFT
Compute the Phase component of the FFT - don't stare at it too long
Compute the Power Spectrum of an image. |
| Comments: |
Require real or integer images of appropriate dimensions.
Note (by B.Schaffer): You can use the transform.dll commands by C.Koch for a FFTW FourieTransform without these limitations.
You can additionally check the packedFFT examples by V.Hou.
There is also an example on how to create and apply masks on FFT for fourier-space filte |
| Acknowledgements: |
Thanks to Bernhard Schafer and Kazuo Ishizuka for advice and assistance |
| Script version: |
1.0 |
| DM/GMS version: |
3.11 |
| Script written as a function: |
No |
| Source: |
Show code |
| Download Source Code: |
 |
| Download Zip File: |
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