From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Parseval's Theorem
Date: Sat, 10 Jan 2009 16:50:03 +0000 (UTC)
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"Matt " <> wrote in message <gkaj8i$qjj$>...

> MATLAB's fft functions are not normalized so as to be orthonormal operators. Therefore, Parseval's theorem will not hold until you normalize them. To normalize them divide fft(A) by numel(A), as in the following example

Sorry, I meant normalize as  fft(A)/sqrt(numel(A))

Also, to change to grayscale do

>>  colormap(gray)

See "help colormap" and "help gray" to fine tune this.