[R] 2D fft DC shift
M. Edward Borasky
znmeb at aracnet.com
Tue Sep 25 04:42:23 CEST 2001
The simplest way to get the "hot spot" in the middle is to pre-multiply the
2D FFT *input* pointwise by a checkerboard pattern of -1s and +1s. For
example, if your input is
a b c d
e f g h
i j k l
m n o p
you would submit
-a b -c d
e -f g -h
-i j -k l
m -n o -p
as input to your 2D FFT. This is from memory; someone with access to an
image processing textbook please correct me if I'm wrong!!!
M. Edward (Ed) Borasky, Chief Scientist, Borasky Research
mailto:znmeb at borasky-research.net mailto:znmeb at aracnet.com
If there's nothing to astrology, how come so many famous men were born on
> -----Original Message-----
> Date: Sun, 23 Sep 2001 20:04:06 -0700 (PDT)
> From: bradley love <bradley_c_love at yahoo.com>
> Subject: [R] 2D fft DC shift
> Hi Everyone,
> Does anyone know how to take the output of a 2D fft()
> and shift the DC component to the center? Is there a
> function that does that?
> if you know, please send me an email.
> thanks for any help!
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