M  A  T  H 
2  1  B 
The original picture 300x300 pixels.  The picture obtained by taking a few Fourier coefficients and then doing the inverse transform. The JPG format itself is based on Fourier, but does it on small blocks in the picture. Here the entire picture is Fourier transformed. 
Here is the C source code from a program written in February 2000
when I was experimenting with higher dimensional moment problems and compared
Fourier with Moments for comparing complexity.
See the paper.
Here are the source files. Just download the gziped tar ball, and unwrap it
with
tar xzf fourier_picture.tgzIn the directory fourier_picture which has appeared, you can then compile and run the code cd fourier_picture make make run make movie
Please send questions and comments to math21b@fas.harvard.edu
Math21b (Exam Group 1) Oliver Knill  Fall 2010 
Department of Mathematics 
Faculty of Art and Sciences 
Harvard University
