net.sf.jaer.eventprocessing.filter
Class RefractoryFilter

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

All Implemented Interfaces:

java.util.Observer

public class RefractoryFilter
extends EventFilter2D
implements java.util.Observer

Adds a refractory period to pixels so that they events only pass if there is sufficient time since the last event from that pixel. Basicall just knocks out redundant events.

Author:

tobi

Field Summary

protected int

refractoryPeriodUs the time in timestamp ticks (1us at present) that a spike needs to be supported by a prior event in the neighborhood by to pass through

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

RefractoryFilter(AEChip chip)

Method Summary

EventPacket	filterPacket(EventPacket in) filters in to out.
static java.lang.String	getDescription()
java.lang.Object	getFilterState() should return the filter state in some useful form
int	getRefractoryPeriodUs() gets the refractory period
int	getSubsampleBy()
void	initFilter() this should allocate and initialize memory: it may be called when the chip e.g.
void	resetFilter() should reset the filter to initial state
void	setRefractoryPeriodUs(int refractoryPeriodUs) sets the refractory delay in us
void	setSubsampleBy(int subsampleBy) Sets the number of bits to subsample by when storing events into the map of past events.
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

refractoryPeriodUs

protected int refractoryPeriodUs

the time in timestamp ticks (1us at present) that a spike needs to be supported by a prior event in the neighborhood by to pass through

Constructor Detail

RefractoryFilter

public RefractoryFilter(AEChip chip)

Method Detail

getDescription

public static java.lang.String getDescription()

filterPacket

public EventPacket filterPacket(EventPacket in)

filters in to out. if filtering is enabled, the number of out may be less than the number put in

Specified by:

filterPacket in class EventFilter2D

Parameters:

in - input events can be null or empty.

Returns:

the processed events, may be fewer in number. filtering may occur in place in the in packet.

getRefractoryPeriodUs

public int getRefractoryPeriodUs()

gets the refractory period

Returns:

delay allowed for spike since last in neighborhood to pass (us)

setRefractoryPeriodUs

public void setRefractoryPeriodUs(int refractoryPeriodUs)

sets the refractory delay in us

Fires a PropertyChangeEvent "refractoryPeriodUs"

Parameters:

refractoryPeriodUs - the address is refractory for this long in us after an event

getFilterState

public java.lang.Object getFilterState()

Description copied from class: EventFilter

should return the filter state in some useful form

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

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

getSubsampleBy

public int getSubsampleBy()

setSubsampleBy

public void setSubsampleBy(int subsampleBy)

Sets the number of bits to subsample by when storing events into the map of past events. Increasing this value will increase the number of events that pass through and will also allow passing events from small sources that do not stimulate every pixel.

Parameters:

subsampleBy - the number of bits, 0 means no subsampling, 1 means cut event time map resolution by a factor of two in x and in y