Natasa Sladoje Joakim Lindblad Ingela Nyström Defuzzification of spatial fuzzy sets by feature distance minimization. 127-141 2011 29 Image Vision Comput. 2-3 http://dx.doi.org/10.1016/j.imavis.2010.08.007 db/journals/ivc/ivc29.html#SladojeLN11