“…However, Zuo, Wang, Zhang, and Zhang (2004) proposed to obtain initial curve by selecting segments from edge map. Comparing with those focusing on geometrical information, many researchers have attempted to utilize color feature of tongue, especially hue-channel value, to obtain initial contour (Shi, Li, & Li, 2013;Yu, Yang, Wang, & Zhang, 2007;Zhai, Lu, & Zhang, 2009). With regard to the curve evolution, Gradient Vector Flow (GVF) (Yu et al, 2007), Double Snake (Zhai et al, 2009), C2G2FSnake (Shi et al, 2013) and Double Geodesic Flow (Shi, Li, Li, & Xu, 2012) were adopted.…”