Re: Find library that support 2Dfft and convolutions

??? wrote:

http://www.jjj.de/fft/fftpage.html#introrem
I find this url that contains some fft source codes
But when I use it,I meet a problem that the image size is not power of  two.
how can I solve it?can I just do padding zero to image?

Zero padding is probably wisest. You probably need to decide what you want to do about the implicit cyclic boundary conditions of the FFT.

And could you tell me the issues about  convolution more detailly
I just think convolution as:
     fft
 i1==>I1                                                         ifft
     fft        ==>  I1*I2(per pixel multiplication)  ==> result
 i2==>I2

Yes. But you have to be a bit careful about the multiplications being complex numbers and if you used an optimised real to complex conjugate transform there will be 4 special cases of pure real number DC, and alternating components. May also be normalisation factors too.

Regards,
Martin Brown
.

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