This brief proposes a generalized framework of median based switching schem
es, called multi-state median (MSM) filter. By using a simple thresholding
logic, the output of the MSM filter is adaptively switched among those of a
group of center weighted median (CWM) filters that have different center w
eights. As a result, the MSM filter is equivalent to an adaptive CWM filter
with a space varying center weight which is dependent on local signal stat
istics. The efficacy of the proposed filter has been evaluated by extensive
simulations.