net.sf.jaer.eventprocessing.filter
Class RepetitiousFilter

java.lang.Object
  net.sf.jaer.eventprocessing.EventFilter
      net.sf.jaer.eventprocessing.EventFilter2D
          net.sf.jaer.eventprocessing.filter.RepetitiousFilter

All Implemented Interfaces:

java.util.Observer

public class RepetitiousFilter
extends EventFilter2D
implements java.util.Observer

An AE filter that filters out boring repetitive events. It does this by maintaining an internal map of boring cells (x,y,type). These are boring because they are repetitive. An event is passed through if its interspike interval (the time since the last event for this cell) is different by a factor of more than ratioShorter to the previous interspike interval. This average dt has a smoothing 'time constant' averagingSamples.

The switch passRepetitiousEvents passes only repetitious events in case those are the interesting ones.

Fires PropertyChangeEvent for the following

• "averagingSamples"
• "minDtToStore"
• "ratioShorter"
• "ratioLonger"

Author:

tobi

Field Summary

protected int	averagingSamples the number of packets processed to average over
protected int	minDtToStore the minimum dt to record, to help reject multiple events from much slower stimulus variation (e.g.
protected int	ratioLonger factor different than previous dt for this cell to pass through filter
protected int	ratioShorter factor different than previous dt for this cell to pass through filter

Fields inherited from class net.sf.jaer.eventprocessing.EventFilter2D

enclosedFilter, out

Fields inherited from class net.sf.jaer.eventprocessing.EventFilter

annotationEnabled, chip, enclosedFilterChain, filterEnabled, log, perf, propertyTooltipMap, support

Constructor Summary

RepetitiousFilter(AEChip chip)

Method Summary

EventPacket	filterPacket(EventPacket in) Subclasses implement this method to define custom processing.
int	getAveragingSamples()
static java.lang.String	getDescription()
int[][][][]	getFilterState() returns array of last event times, x,y,type,[t0,t1], where t0/t1 are the last two event times, t0 first.
int	getMinDtToStore()
boolean	getPassRepetitiousEvents()
int	getRatioLonger()
int	getRatioShorter()
void	initFilter() this should allocate and initialize memory: it may be called when the chip e.g.
boolean	isGeneratingFilter()
void	resetFilter() should reset the filter to initial state
void	setAveragingSamples(int averagingSamples) sets the number of packets to smooth dt for a pixel over
void	setMinDtToStore(int minDtToStore)
void	setPassRepetitiousEvents(boolean passRepetitiousEvents)
void	setRatioLonger(int ratioLonger)
void	setRatioShorter(int ratioShorter)
void	update(java.util.Observable o, java.lang.Object arg)

Methods inherited from class net.sf.jaer.eventprocessing.EventFilter2D

checkOutputPacketEventType, checkOutputPacketEventType, getEnclosedFilter, resetOut, setEnclosedFilter, setFilterEnabled

Methods inherited from class net.sf.jaer.eventprocessing.EventFilter

getChip, getEnclosedFilterChain, getEnclosingFilter, getPrefs, getPropertyChangeSupport, getPropertyTooltip, isAnnotationEnabled, isEnclosed, isFilterEnabled, prefsEnabledKey, setAnnotationEnabled, setChip, setEnclosed, setEnclosedFilter, setEnclosedFilterChain, setEnclosingFilter, setPreferredEnabledState, setPrefs, setPropertyTooltip

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ratioShorter

protected int ratioShorter

factor different than previous dt for this cell to pass through filter

ratioLonger

protected int ratioLonger

factor different than previous dt for this cell to pass through filter

minDtToStore

protected int minDtToStore

the minimum dt to record, to help reject multiple events from much slower stimulus variation (e.g. 50/100 Hz)

averagingSamples

protected int averagingSamples

the number of packets processed to average over

Constructor Detail

RepetitiousFilter

public RepetitiousFilter(AEChip chip)

Method Detail

getDescription

public static java.lang.String getDescription()

isGeneratingFilter

public boolean isGeneratingFilter()

getFilterState

public int[][][][] getFilterState()

returns array of last event times, x,y,type,[t0,t1], where t0/t1 are the last two event times, t0 first.

Specified by:

getFilterState in class EventFilter

resetFilter

public void resetFilter()

Description copied from class: EventFilter

should reset the filter to initial state

Specified by:

resetFilter in class EventFilter

getAveragingSamples

public int getAveragingSamples()

setAveragingSamples

public void setAveragingSamples(int averagingSamples)

sets the number of packets to smooth dt for a pixel over

getMinDtToStore

public int getMinDtToStore()

setMinDtToStore

public void setMinDtToStore(int minDtToStore)

getRatioShorter

public int getRatioShorter()

setRatioShorter

public void setRatioShorter(int ratioShorter)

getRatioLonger

public int getRatioLonger()

setRatioLonger

public void setRatioLonger(int ratioLonger)

update

public void update(java.util.Observable o,
                   java.lang.Object arg)

Specified by:

update in interface java.util.Observer

initFilter

public void initFilter()

Description copied from class: EventFilter

this should allocate and initialize memory: it may be called when the chip e.g. size parameters are changed after creation of the filter

Specified by:

initFilter in class EventFilter

filterPacket

public EventPacket filterPacket(EventPacket in)

Description copied from class: EventFilter2D

Subclasses implement this method to define custom processing.

Specified by:

filterPacket in class EventFilter2D

Parameters:

in - the input packet

Returns:

the output packet

getPassRepetitiousEvents

public boolean getPassRepetitiousEvents()

setPassRepetitiousEvents

public void setPassRepetitiousEvents(boolean passRepetitiousEvents)