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How to get Fourier descriptor

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Ferdi Ferdi

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Dec 30, 2009, 12:11:20 AM12/30/09
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Dear all,
I'm newbie in using matlab. I want to extract fourier descriptor of my images. Could you please explain to me how to do this in matlab?

Thank you very much for your help.

Ferdi
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Matt J

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Dec 30, 2009, 12:27:04 AM12/30/09
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"Ferdi Ferdi" <muhf...@yahoo.com> wrote in message <hhendo$ick$1...@fred.mathworks.com>...

Do you have data arrays x(n),y(n) of coordinates of some image object boundary?

If so, then you would just do

FourierDescriptorArray = fft(x+y*i)


Ferdi Ferdi

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Dec 31, 2009, 2:19:04 AM12/31/09
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Dear Matt,
Thank you very much for your help. But what do you mean by
(x+y*i). What is i in this context?

Regards,

Ferdi

"Matt J " <mattja...@THISieee.spam> wrote in message <hheob7$fev$1...@fred.mathworks.com>...

Matt J

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Dec 31, 2009, 12:41:11 PM12/31/09
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"Ferdi Ferdi" <muhf...@yahoo.com> wrote in message <hhhj97$bcm$1...@fred.mathworks.com>...

> Dear Matt,
> Thank you very much for your help. But what do you mean by
> (x+y*i). What is i in this context?


The function i() in MATLAB returns sqrt(-1):

>> i

ans =

0 + 1.0000i

Ferdi Ferdi

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Jan 2, 2010, 9:25:06 AM1/2/10
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Thank you very much matt..
Now i understand, i means for complex number.
I use fd for clustering images based on shape.
but i get poor result :( anybody can help me with this matter?

"Matt J " <mattja...@THISieee.spam> wrote in message <hhinnn$ap8$1...@fred.mathworks.com>...

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