Negative Weighted Repeated Pseudo-median Filter

In this paper, the Negative Weighted Repeated Pseudo-median Filter (NWRPM), a new method combined the characteristics of repeated median filter (RM), weighted median filter and pseudo-median filter (PM), is proposed so as to be applicable for the low-power system with limited processing and storage capacity such as wireless sensor etc. The NWRPM adopts PM to simplify the computations of median filter and uses local linear fitting of RM to overcome the difficulties of median´s dealing with local trends. Meanwhile, by applying the negative weighting method originated from the Arce´s negative weighted median filter, the NWRPM achieves the characteristic of frequency selection. According to Mallows method presented by Arce, the weight coefficients of the NWRPM are derived from the filtering coefficients of FIR filter with the desired spectral response to approach the frequency response of the corresponding FIR filter. The simulation results show that the frequency selection characteristic of the NWRPM approximates to the frequency response of FIR more than those typical weighted median filter.