function testGauss
F=imread('kids.tif');
times=[0]; %bogus value

for sigma = 1:15  %backwards: 15:-1:1
    tic;
    H=imfilter(F, Gauss(sigma), 'conv', 'replicate');
    times=[times; toc];
    imshow(H);
    drawnow;
end

times(2:end)
plot(times(2:end))