Function normalize

examples/image_processing/gradient_diffusion.cpp:19–23

static const unsigned ITERS = 64;

array normalize(const array &p_in) {
    float mx = max<float>(p_in);
    float mn = min<float>(p_in);
    return (p_in - mn) / (mx - mn);
}

array sobelFilter(const array &p_in) {
    int w = 5;