repl.m

this is a very very very nice code

%Creates an output image which is the input image with reflection about the
%borders for ct pixels
function out = repl(in, ct)

out = zeros(size(in,1)+2*ct, size(in,2)+2*ct);
M = size(out,1);
N = size(out,2);

out(ct+1:M-ct, ct+1:N-ct) = in;

for i = 1:ct
    out(ct+1-i, :) = out(ct+i, :);
    out(M-ct+i, :) = out(M-ct+1-1, :);
end

for i = 1:ct
    out(:, ct+1-i) = out(:, ct+i);
    out(:, N-ct+i) = out(:, N-ct+1-1);
end