function result = apply_lowpass_filter(image, cutoff)
%   function result = apply_lowpass_filter(image, cutoff)
[f1,f2] = freqspace(size(image),'meshgrid');
Hd = ones(size(image));
r = sqrt(f1.^2 + f2.^2);
Hd(r>cutoff) = 0;
%Hd = (Hd + rot90(Hd,1) + rot90(Hd,2) + rot90(Hd,3)) / 4; 
result = ifft2(fft2(image) .* fftshift(Hd));

     

