“…The idea of using polygonal Markov field models for this purpose can be traced back to Clifford and Middleton (1989); see also Clifford and Nicholls (1994). Since the Monte Carlo methods employed at that time turned out to be rather onerous, the theme was not picked up again until the mid-2000s (Paskin and Thrun, 2005) when further theoretical results (Schreiber, 2005) motivated the development of conceptually and computationally easier algorithms (Kluszczyński et al, 2005(Kluszczyński et al, , 2007Schreiber and Lieshout, 2010;Lieshout, 2012). In the meantime, Voronoi (Green, 1995;Heikkinen and Arjas, 1998;Møller and Skare, 2001) and triangulation (Nicholls, 1998) models had also been tried.…”