On the synthesis of median filter systems

In this paper, we address the problem of median filtering synthesis, that is, the design of a median filter system realization that will satisfy a given set of specifications. In particular, we address the problem of a cascade median filter realization, where the performance of a median filter is achieved through the cascade of several median filters of smaller window size. Because of the nonlinear nature of these filters, a statistical performance criterion is chosen for the system specifications. In order to evaluate the output of the cascade filter, a method is developed which finds the statistics of the roots of median filters, where roots are signals obtained after several median filter passes. Finally, a VLSI implementation for a cascade median filter system is presented.