Fourier transforming TIFF (2D) images

*To*: mathgroup at christensen.Cybernetics.NET*Subject*: [mg414] Fourier transforming TIFF (2D) images*From*: dmwood at sst.nrel.gov (David M. Wood)*Date*: Thu, 19 Jan 95 17:29:47 MST

Dear MathGroup, This problem has probably arisen many times before, but here it is again: I have a gray-scale scanned image, stored as a TIFF file [8 bits or 256 levels per pixel], and would like to (1) convert the intensity value for each pixel into a floating-point value, say between 0. and 1., and (2) Fourier transform the resulting (presumably two-dimensional) array. Has anyone gone through the trouble to look up the TIFF standard and write a utility Notebook to transform a TIFF into such an array? [The image turns out to be a photomicrograph of an artifically periodic structure, and I'd like to compare its *predicted* diffraction pattern (for visible light, as it turns out, as you'd expect from the fact the image is a photograph) with its observed light diffraction pattern, which is proportional to the Fourier transform of the deviation from 1 of its index of refraction.] Many thanks! 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 :(