Noise

i = imread("spillway.tif");
figure(1), imshow(i)

%add noise
in = imnoise(i,'gaussian');
figure(2), imshow(in)

%remove noise
irn = imfilter(in, fspecial('average'));
figure(3), imshow(irn)

%add noise in transform domain remove it,
%and then compare the original image and the final
% one (the one that is filtered)
i_fft = fft(i);
in_fft = imnoise(i_fft, 'gaussian');
denoise = imfilter(in_fft, fspecial('average'));

figure(5), imshow(ifft(denoise), [])