“…Various forms of IDO and HT (Wildes, 1997, Zuo et al, 2006, Liu et al, 2005, Jan et al, 2013, Tan et al, 2010 are proposed in the literature. Apart from these two techniques, other boundary based methods found in the literature are, active shape models (Abhyankar and Schuckers, 2006), binary morphology and image statistics (Kennell et al, 2006), adaptive binarisation (Basit and Javed, 2007), Adaboost cascading and elastic model (He et al, 2009), Geodesic active counter (Shah and Ross, 2009), and eyeball model (Baek et al, 2013).…”