I=rand(240, 320);
[m, n]=size(I);
I_f=zeros(m,n);
d=3;
q=(d-1)/2;
for x=q:n
    for y=q:m
        for r=-q:q
            for p=-q:q
                I_f(x,y)=I(x+p,y+r);
            end
        end
    end
end