“…Further, most hybrid methods include some or other form of grouping mechanism to group the edges that possibly belong to the same ellipse (Chia et al, 2011;Hahn et al, 2008;Kawaguchi and Nagata, 1998b;Kim et al, 2002;Mai et al, 2008). Finally, there are some essential ellipse refinement and selection steps to deal with the outliers and reduce false positives (Basca et al, 2005;Cheng, 2006;Ji and Haralick, 2001;Princen et al, 1994;Qiao and Ong, 2007;Wang et al, 2007;Prasad et al, 2010e)). …”