median

A median filter, a variant FIR lowpass filter.

Syntax

ares median asig, ksize, imaxsize [, iskip]

Initialization

imaxsize -- the maximun size of the window used to select the data.

iskip -- initial disposition of internal data space. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0.

Performance

asig -- input signal to be filtered

ksize -- size of the window over which the input is to be filtered. It must not exceed the maximum window size; if it does it is truncated.

median is a simple filter that retuns the median value of the last ksize values. It has a lowpass action. The efficiency decreases as the window size increases.

Examples

Here is an example of the median opcode. It uses the file median.csd.

<CsoundSynthesizer>

<CsInstruments>
sr = 44100
kr = 441
ksmps = 100
nchnls = 1

instr 1
  a1  oscil  30000, 10, 1
  a2  median a1, 5, 8
  out a2
endin
</CsInstruments>

<CsScore>
f1 0 4096 10 1
i 1 0 0.1 
e

</CsScore>

</CsoundSynthesizer>

See also

Standard filters: Variant FIR lowpass filter

Credits

Author: John ffitch
University of Bath
May 2010

New in Csound version 5.13