Anguelov, RoumenRohwer, Carl (Carl H.)2010-07-152010-07-152009Anguelov, R & Rohwer, C 2009, 'LULU operators for functions of continuous argument', Quaestiones Mathematicae, vol. 32, pp. 1-21. [http://www.nisc.co.za/journals?id=7]1607-3606http://hdl.handle.net/2263/14456The LULU operators, well known in the nonlinear multiresolution analysis of sequences, are extended to functions defined on a continuous domain, namely, a real interval. We show that the extended operators replicate the essential properties of their discrete counterparts. More precisely, they form a fully ordered semi-group of four elements, preserve the local trend and the total variation.enNISCNonlinear smoothingLULU operatorsVariation preservationSmoothing (Numerical analysis)Image processingPostprint Article