fourier01_01.r

#required packages:
require(jpeg)

#Read a jpeg from a website and store as matrix "mat_clown"
con       <- file("http://4.bp.blogspot.com/-uObQLjPG8Xg/VceaZNyI-NI/AAAAAAAAx0o/ZlcTTB1pomU/s1600/fourier_efteling.jpg", "rb")
#make sure 'n' is big enough to hold your entire file:
jpg_clown <- readBin(con, "raw", n = 3e4)
close(con)
rm(con)
mat_clown <- readJPEG(jpg_clown)
rm(jpg_clown)

#rotate the matrix to its intended position
rotate    <- function(x) t(apply(x, 2, rev))
mat_clown <- rotate(mat_clown)