Questions about FFT2

[Simoes Vincent]

Hi,
I'm a frensh student in a school of image processing and i have to try to do image processing with a FPGA.

For that, i need to use the fft2. I know how to do a fft2 on your software using fft2() and ifft2() but i can't use it on a FPGA. Thus, i want to rewrite the function fft2 and ifft2. I have try with the formuls, I have done that on a image 512x512 divided on matrice 8x8 to do several fft2. But it takes too long to be interessant for me !
That's why i'm writing to you about your function fft2. Can you tell me how you do it ? Maybe give me your algorithm as your software is a free one.
After the installation of octave, i have found some files which can help me for sure but i dont know how to open it, it is fft2.oct and ifft2.oct. I hope you can help me on this subject.

Moreover, i want to congrats you for your software, it is very useful to work on my own at home and to avoid Matlab, witch is too expensive for a single person.

I look forward to hearing from you soon
Thanks a lot for your help

SIMOES Vincent