get_norm.m

this is a very very very nice code

function nrm = get_norm(Iy,Ix,pix_set)

nrm = zeros(size(Iy));
for k = 1:size(pix_set,1)
    y = pix_set(k,1);
    x = pix_set(k,2);
    nrm(y,x) = sqrt(Iy(y,x)^2 + Ix(y,x)^2);
end