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ArgusMagnus

FFT / IFFT Effect

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I feel like this is ready to be released into the wild: https://onedrive.live.com/redir?resid=429F16CCEF18E484!339757&authkey=!AJ0aYSIXTh_4Jhs&ithint=folder%2ctxt

(Copy the files "ArgusPaintNet.FTT.dll" and "ArgusPaintNet.Shared.dll" and the folder "NativeBinaries" to the "paint.net/Effects" folder)

 

 

This Plugin contains 4 effects related to Fast Fourier Transform and Signal Processing in the Frequency Domain:

 

1. Transform->Fast Fourier Transform: Transforms either intensity image or one of the channels (R,G,B ) to and from the frequency domain. The transformed image contains the magnitude information in the R and G values and the phase information in the B value (which basically means: don't change the B value of any pixel too much are at all if you want to get a meaningful result when transforming back).

If you want to get a meaninful result when transforming back, there are two limitations: 1. Don’t change the B component (the phase information is important), 2. Non-rectangular Selections won’t work.

 

2. Signal Processing->Low Pass Filter: The same as using the transform effect, removing (setting to black or transparent) all pixel outside a rectangle around the center and transforming back only this is faster, more accurate (less information is lost) and easier to control

 

3. Signal Processing->High Pass Filter: The same as using the transform effect, removing all pixels inside a rectangle around the center and transforming back (again, faster, more accurate, easier controlled)

 

5. Signal Processing->Band Pass Filter: Combination of Low and High Pass Filter.

 

Example: FFT

lw59GV.png

 

Example images (high pass filtered, adjusted and blended together):

09sGip.pngJKzh9N.png

 

 

The plugin actually uses the FFTW library (fftw.org), I have not written the transformation code myself (mainly for performance reasons)

Edited by ArgusMagnus
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