“…Vanishing points are valuable for camera calibration (Kosecka and Zhang 2002;Cipolla et al, 1999;Caprile andTorre 1990, andTardif 2009), estimation of rotation angles (Kosecka and Zhang 2002;Antone andTeller 2000, andDenis et al 2008), and more importantly 3D reconstruction (Parodi andPiccioli 1996, andCriminisi et al, 2000). In order to find vanishing points, different methods of straight line clustering are available (Bazin et al, 2012). There are four main categories for these methods based on: 1) Hough Transform (HT), 2) Random Sample Consensus (RANSAC), 3) Exhaustive Search on some of the unknown entities, and 4) Expectation Maximization (Bazin et al, 2012).…”