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 :(