A = imread('tree.jpg');
size(A)
imshow(A, 0)
[U, S, V] = svd(A);
imshow(U*S*V', [0, 256])
imshow(S, [0,256])

function T = truncar(M, k)
T = M;
s = size(T);
n = min(s(1), s(2));
for i = k+1:n
T(i,i) = 0;
end
end

T = truncar(S, 1);
imshow(U*T*V', [0, 256]);

T = truncar(S, 5);
imshow(U*T*V', [0, 256]);

T = truncar(S, 20);
imshow(U*T*V', [0, 256]);

T = truncar(S, 50);
imshow(U*T*V', [0, 256]);