After class last Thursday a few people showed some interest in how one might take Fourier transforms of images, along the lines of the Mona Lisa example we did in class. I looked around and couldn't find a simple Internet interface where one can do this, but if you're still interested it shouldn't be horrible to just do this using python, a free math language that is "the wave of the future" in research.
This will probably take an hour or two if you still want to do it, but it's worth it if you plan to do more astronomy or do research---I use python daily for mine, for instance. Below are instructions on how to get it all going.
I, Marion, or Luke are glad to help out with any of this in person, and I have an example program I wrote last year that does an FT of an image I could share if there's interest---email astro16.
step 1: get python
go here for installation instructions:
and lots of useful links here:
step 2: load in image from file to python
this will store the image as an array, just a table of numbers basically
step 3: fourier transform image
explained here
(though your file won't be in fits format, but that doesn't matter---once it's an array you can use the python fft packages this post describes; note fft=fast fourier transform, just an algorithm for doing fts)
step 4: plot it
gives you many ways to plot in python. you will want a 2-d method since you have an image to plot
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