function out = fftprep(inp,m)
%
% FFTPREP
%
%	out = fftprep(inp)
%		embeds input image in the center of a blank square image
%		whose size is a power of two.
%
%	out = fftprep(inp,m)
%		embeds input image in the center of a blank square image of size m.
%

%	Author:  John S. Loomis  6 March 2000

inp = im2double(inp);
s = size(inp);
ms = max(s);

n2 = 1;
while (n2<ms)
   n2 = n2*2;
end
if (nargin<2)
   m = n2;
elseif (m<n2)
   m = n2;
end

out = zeros(m,m);

row_offset = floor((m - s(1)+1)/2);
col_offset = floor((m - s(2)+1)/2);

out(1+row_offset:s(1)+row_offset,1+col_offset:s(2)+col_offset) = inp;

Published with MATLAB® 7.6