fftshift

[siddy]

Hi all,

     Again, trying to transcode some matlab ideas to IPP based C++ : is there a similar function in IPP that

performs the fftshift operation, as in Matlab? (shift zero frequence to the center of the space). Or, if someone can confirm that the FFTFwd etc.

already result in transforms in this format, and that fftshift operation is not required. 

Thanks,

Sid.

[Chuck_De_Sylva]

Can you submit a sample of what you are trying to do in Matlab code? Thanks.

[siddy]

F = fftshift(fft2(I)) where I is MxN image. Q: is fftshift needed for IPP fft, and if yes, how to do it? Sid.

[John_M_1]

Ever got an answer to your question, siddy?

[Chao_Y_Intel]

Hello,

When I check the fftshift function here:  http://www.mathworks.com/help/matlab/ref/fftshift.html

For vectors, fftshift(X) swaps the left and right halves of X. For matrices, fftshift(X) swaps the first quadrant with the third and the second quadrant with the fourth.

Could you try to use the ippiCopy_xxx function to swaps these data one by one block?

Regards,
Chao

[Royi]

@Chao,

It would be great to have something like that out of the box.
Mainly that it is crucial when visualizing the Spectrum.

Thank You.