“…Machine vision has been widely used in field automated guidance system, such as harvesting (Benson et al, 2003;Debain et al, 2000;Ollis and Stentz, 1996), cultivating (Hague and Tillett,2001;Olsen, 1995;Rovira Más, 2005), and spraying (Sanchiz et al, 1998).…”