mediank

mediank — A median filter, a variant FIR lowpass filter.

Description

Implementation of a median filter.

Syntax

kres mediank kin, 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

kin -- krate value 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.

mediank 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 mediank opcode. It uses the file mediank.csd.

Example 467. Example of the mediank opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

<CsoundSynthesizer>
<CsOptions>
-n
</CsOptions>
<CsInstruments>
sr = 44100
kr = 147
ksmps = 300
nchnls = 1

instr 1
  k1  oscil  100, 10, 1
  k2  mediank k1, 5, 8
  printk 0, k2
endin
</CsInstruments>
<CsScore>
f1 0 4096 10 1
i 1 0 1 
e

</CsScore>
</CsoundSynthesizer>


Credits

Author: John ffitch
University of Bath
May 2010

New in Csound version 5.13