A median filter is a non-linear and lossy process, so it doesn't have a closed form frequency response as would a FIR filter (say a box filter of the same length) in an LTI system.
- But how closely can something similar to a frequency response of a median filter be approximated?
- How would this scale with the length of a median filter?
- Under what conditions or for what class of signals might this approximation be ballpark "close"?
- For what class of signals might this approximation be very inaccurate?
- What kinds of frequency domain distortion or additive noise does a median filter produce?