Generalized median filters for biological signal processing

Median filtering is a nonlinear filtering technique which is known for preserving sharp changes in signals and for being particularly effective in removing impulsive noise and reducing the waveform into the root signals. We compare the recently introduced Smoothed Median Filters (SMF) with the normal Median Filters (MF) and with moving averaging filters in biological signal processing. The examples indicate that the SMF's extract efficiently the trends of different durations from the signals. The SMF's contain linear substructures for signal smoothing and the median is taken over the outputs of the substructures. The number of compare/swap operations is thus reduced substantially although the statistical properties and the root signals of the SMF's are practically the same as those of the normal MF's.