Smoothed median filters with FIR substructures
Pekka Heinonen, Yrjo A. Neuvo · 2005
In this paper we introduce a new generalized class of Median Filters (MF) which we call Smoothed Median Filters (SMF). The input signal x(n) is filtered with M linear phase FIR filters and the output of the SMF is the median of the outputs of the FIR filters. The statistical properties of the SMF's are analyzed for input signals with Gaussian, double exponential, and uniform density functions. It is shown that SMF's have essentially the same statistical properties and same type of root signals as the conventional MF's. SMF's preserve corner points and ramps and attenuate impulsive type noise components effectively. An interesting subclass of the SMF's requiring only two scaling multipliers and three data sorting operations irrespective of the filter length is introduced.