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Followup on Fourier transforming TIFF images

• To: mathgroup at christensen.cybernetics.net
• Subject: [mg441] Followup on Fourier transforming TIFF images
• From: dmwood at sst.nrel.gov (David M. Wood)
• Date: Thu, 2 Feb 95 15:39:55 MST

Dear Mathgroup,

   A followup on my own question about Fourier transforming TIFF images.  
Strictly speaking this is *not* a Mathematica remark, but the solution 
below appears, at present, to be *the* way to go.

   Andrew Tennant recommended using the FFT extensions (developed by A. Arlo 
Reeves) to the public domain Mac image utility Image (developed for the 
National Institute of Health). These extensions currently act on 2^n x 2^n 
selections from TIFF files, work very well, and do precisely what I want, so 
I have abandoned a Mathematica route, which would not have been ideal for 
heavy number crunching anyway.  You can also *inverse* Fourier transform your 
Fourier transform, to compare with the original image.  What fun!

   Both the Image package and the FFT extensions are available via anonymous 
FTP from 

ftp://ra.nrl.navy.mil/MacSciTech/imaging/NIH_Image/
and
ftp://ra.nrl.navy.mil/MacSciTech/imaging/imagefft/
respectively.

   "Robert A. Day" <rockyd at netcom.com> also suggested using Image, which will
save TIFF images as lists of ASCII numbers.

   Andrew also has pointed out another potentially useful Mac utility named
DigitalFileter, available in

ftp://ra.nrl.navy.mil/MacSciTech/dsp/

This I haven't had a chance to evaluate.

David M. Wood           ||      Solid State Theory Group
dmwood at nrel.nrel.gov    ||      Branch 4510 
Phone: (303) 384-6642   ||      National Renewable Energy Laboratory
Fax:   (303) 384-6531   ||      1617 Cole Blvd., Golden, CO 80401-3393
No NeXTMail here please :(