Dietrich Van der Weken Valérie De Witte Mike Nachtegael Stefan Schulte Etienne E. Kerre Colour Image Comparison Using Vector Operators. 639-656 2008 Fuzzy Sets and Their Extensions: Representation, Aggregation and Models http://dx.doi.org/10.1007/978-3-540-73723-0_33 series/sfsc/2008-220 db/series/sfsc/sfsc220.html#WekenWNSK08