function [Im] = assembly(Gauss, Details, coefs)

l = length(Details);
four = Gauss{l};
for i = l:-1:1
    Im = four;
    s1 = size(Im);
    s2 = size(Details{i});

    if s1(1) < s2(1)
        Im(s1(1) + 1, :) = mean(Im(:))*ones(1, s1(2));
        s1 = size(Im);
    end

    if s1(2) < s2(2)
        Im(:, s1(2) + 1) = mean(Im(:))*ones(s1(1), 1);
    end

    Im = Im + Details{i}*coefs(i);
    s = size(Im);
    four = zeros(s*2);

    for i = 1:s(1)
        for j = 1:s(2)
            four((2*i - 1):(2*i), (2*j - 1):(2*j)) = Im(i, j)*ones(2);
        end
    end
end
end


function [Gauss, Details] = gauss(Im, steps)
    small = Im;
    m = mean(Im(:));
    for step = 1:steps
        P = small;

        s = size(P);

        G = m*ones(s);
        D = m*ones(s);
        small = zeros(s/2);

        for i = 2:2:s(1)
            for j = 2:2:s(2)
                frame = P((i-1):i, (j-1):j);
                av = mean(frame(:));
                G((i-1):i, (j-1):j) = av*ones(2);
                D((i-1):i, (j-1):j) = frame - av*ones(2);
                small(i/2, j/2) = av;
            end
        end

        if rem(s(1), 2) == 1
            G(s(1), :) = min(G(:))*ones(1, s(2));
            D(s(1), :) = zeros(1, s(2));
        end
        if rem(s(2), 2) == 1
            G(:, s(2)) = min(G(:))*ones(s(1), 1);
            D(:, s(2)) = zeros(s(1), 1);
        end

        Gauss{step} = G - max(G(:));
        Details{step} = D - max(D(:));
    end
end