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;
Maintained by John
Loomis, last updated 8 March 2000