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fft application? [message #31573] Fri, 02 August 2002 07:46
bin_zheng_99 is currently offline  bin_zheng_99
Messages: 6
Registered: July 2002
Junior Member
Hi, All,

I try to do template matching using IDL and I run the IDL code:
...
img4 = rotate (img3, 2)
Result = float (fft(fft(img) * fft(img4),/inverse))
...

based on the code used in Matlab image processing toolbox:
C = real(ifft2(fft2(bw) .* fft2(rot90(a,2),256,256))); (bw, a are
two images)
the max(C) is 51.

But on IDL55 the Max value is 0.00013. I use the same images as in
the Mablab.

So, I wonder are there some serious differences between the fft in
IDL and in Matlab? How can I improve my program to get good result?

Thanks very much for any suggestions, ideas, or help,

Helen
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