Function loop9::loop9

pub fn loop9<Pixel, Callback>(
    img: ImgRef<Pixel>, 
    left: usize, 
    top: usize, 
    width: usize, 
    height: usize, 
    cb: Callback
) where
    Pixel: Copy,
    Callback: FnMut(usize, usize, Triple<Pixel>, Triple<Pixel>, Triple<Pixel>),