Re: FFT implementation in ImageJ

Posted by Student1 on
URL: http://imagej.273.s1.nabble.com/FFT-implementation-in-ImageJ-tp5008239p5008326.html

Hi Burger,

I kind of wanted to implement the FFT by hand instead of using a library because I really want to understand how the FFT works and make sure I got the implementation correct. I know that combining the complex and real array is doubling the size of the array and I don’t know exactly how to fix that. I don’t thinks theres a problems in the rest of the code I implemented.

Thanks.

Mariam Dost


On Jun 19, 2014, at 9:46 AM, Burger Wilhelm <[hidden email]> wrote:

> Hello Miriam,
>
> have you considered the FFT implementation in Apache Commons Math?:
> http://commons.apache.org/proper/commons-math/apidocs/org/apache/commons/math3/transform/FastFourierTransformer.html
>
> Works "out of the box" and results are correct.
>
> --Wilhelm Burger
>
> ________________________________________
> From: ImageJ Interest Group [[hidden email]] On Behalf Of Student1 [[hidden email]]
> Sent: Wednesday, June 18, 2014 23:58
> To: [hidden email]
> Subject: Re: FFT implementation in ImageJ
>
> Hi,
>
> First of all thanks for everybody’s input. I implemented an FFT algorithm by basically looking it up online and I am tracing through the calculation by hand to get a better understanding of the FFT. The FFT I implemented does not produce the image that should be produced by ImageJ. I was wondering if anyone can see where I am going wrong with my calculation. My work is here:
>
> http://stackoverflow.com/questions/24291896/fft-image-is-not-the-same-as-the-fft-image-produced-in-imagej
>
> Thanks.
>
> Mariam Dost

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