Moving-median-filter

Concept Block

 input
 +
 |
 +--+--+
 | S/H | <-----------------+ sampling time
 +--+--+
 |
 v
 +------------------+--------------------+
index +-->+ DEMUX |
 +----+------+------+----------------+---+
 | | | |
 +--+-+ +--+-+ +--+-+ +--+-+
 | B0 | | B1 | | B3 | . . . . . | Bn | <+ buffer
 +-+--+ +-+--+ +-+--+ +-+--+ n is size+1
 | | | |
 +---+------+------+----------------+----+
 | SORT |
 +----+------+------+----------------+---+
 | | | |
 +--+-+ +--+-+ +--+-+ +--+-+
 | S0 | | S1 | | S2 | . . . . . | Sn | <+ sorted list
 +-+--+ +-+--+ +-+--+ +-+--+
 | | | |
 +------+------++---------------+
 |
 +--------+--------+
 | Fill index / 2 | <+ list
 +--------+--------+ med value
 |
 v
 filtered

Code usage

/* Include library */
#include "moving-median.h"
/* Filter objects */
movingMedian_t med_filter;
movingMedian_t med_filter_2;
void main()
{
 /* Initialization of filters */
 moving_median_create(&med_filter, 11, 100); /* filter size 11, sample time 100ms */
 moving_median_create(&med_filter_2, 29, 150); /* filter size 29, sample time 150ms */
 /* wait for 1 maximum sample time */
 delay(150);
 while(1)
 {
 signal = signal_source(); /* signal source function may ADC, Capture count, sensor data*/
 /* Filter process
 * 
 * call this function maximum passible short time
 */
 moving_median_filter(&med_filter, signal);
 moving_median_filter(&med_filter_2, signal);
 process_or_print = med_filter.filtered;
 process_or_print = med_filter_2.filtered;
 }
}

Filter images

Refer other filters