org.bytedeco.opencv.opencv_video

Class BackgroundSubtractorKNN

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.opencv.opencv_core.Algorithm

org.bytedeco.opencv.opencv_video.BackgroundSubtractor

org.bytedeco.opencv.opencv_video.BackgroundSubtractorKNN

All Implemented Interfaces:

AutoCloseable

@Namespace(value="cv")
 @Properties(inherit=opencv_video.class)
public class BackgroundSubtractorKNN
extends BackgroundSubtractor

\brief K-nearest neighbours - based Background/Foreground Segmentation Algorithm.

The class implements the K-nearest neighbours background subtraction described in \cite Zivkovic2006 . Very efficient if number of foreground pixels is low.

Nested Class Summary

Nested classes/interfaces inherited from class org.bytedeco.javacpp.Pointer

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
BackgroundSubtractorKNN(Pointer p) Pointer cast constructor.

Method Summary

Modifier and Type	Method and Description
boolean	getDetectShadows() \brief Returns the shadow detection flag
double	getDist2Threshold() \brief Returns the threshold on the squared distance between the pixel and the sample
int	getHistory() \brief Returns the number of last frames that affect the background model
int	getkNNSamples() \brief Returns the number of neighbours, the k in the kNN.
int	getNSamples() \brief Returns the number of data samples in the background model
double	getShadowThreshold() \brief Returns the shadow threshold
int	getShadowValue() \brief Returns the shadow value
void	setDetectShadows(boolean detectShadows) \brief Enables or disables shadow detection
void	setDist2Threshold(double _dist2Threshold) \brief Sets the threshold on the squared distance
void	setHistory(int history) \brief Sets the number of last frames that affect the background model
void	setkNNSamples(int _nkNN) \brief Sets the k in the kNN.
void	setNSamples(int _nN) \brief Sets the number of data samples in the background model.
void	setShadowThreshold(double threshold) \brief Sets the shadow threshold
void	setShadowValue(int value) \brief Sets the shadow value

Methods inherited from class org.bytedeco.opencv.opencv_video.BackgroundSubtractor

apply, apply, apply, apply, apply, apply, getBackgroundImage, getBackgroundImage, getBackgroundImage

Methods inherited from class org.bytedeco.opencv.opencv_core.Algorithm

clear, empty, getDefaultName, position, read, save, save, write, write, write

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, availablePhysicalBytes, calloc, capacity, capacity, close, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, formatBytes, free, hashCode, isNull, isNull, limit, limit, malloc, maxBytes, maxPhysicalBytes, memchr, memcmp, memcpy, memmove, memset, offsetof, parseBytes, physicalBytes, position, put, realloc, referenceCount, releaseReference, retainReference, setNull, sizeof, toString, totalBytes, totalPhysicalBytes, withDeallocator, zero

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BackgroundSubtractorKNN

public BackgroundSubtractorKNN(Pointer p)

Pointer cast constructor. Invokes Pointer.Pointer(Pointer).

Method Detail

getHistory

public int getHistory()

\brief Returns the number of last frames that affect the background model

setHistory

public void setHistory(int history)

\brief Sets the number of last frames that affect the background model

getNSamples

public int getNSamples()

\brief Returns the number of data samples in the background model

setNSamples

public void setNSamples(int _nN)

\brief Sets the number of data samples in the background model.

The model needs to be reinitalized to reserve memory.

getDist2Threshold

public double getDist2Threshold()

\brief Returns the threshold on the squared distance between the pixel and the sample

The threshold on the squared distance between the pixel and the sample to decide whether a pixel is close to a data sample.

setDist2Threshold

public void setDist2Threshold(double _dist2Threshold)

\brief Sets the threshold on the squared distance

getkNNSamples

public int getkNNSamples()

\brief Returns the number of neighbours, the k in the kNN.

K is the number of samples that need to be within dist2Threshold in order to decide that that pixel is matching the kNN background model.

setkNNSamples

public void setkNNSamples(int _nkNN)

\brief Sets the k in the kNN. How many nearest neighbours need to match.

getDetectShadows

@Cast(value="bool")
public boolean getDetectShadows()

\brief Returns the shadow detection flag

If true, the algorithm detects shadows and marks them. See createBackgroundSubtractorKNN for details.

setDetectShadows

public void setDetectShadows(@Cast(value="bool")
                             boolean detectShadows)

\brief Enables or disables shadow detection

getShadowValue

public int getShadowValue()

\brief Returns the shadow value

Shadow value is the value used to mark shadows in the foreground mask. Default value is 127. Value 0 in the mask always means background, 255 means foreground.

setShadowValue

public void setShadowValue(int value)

\brief Sets the shadow value

getShadowThreshold

public double getShadowThreshold()

\brief Returns the shadow threshold

A shadow is detected if pixel is a darker version of the background. The shadow threshold (Tau in the paper) is a threshold defining how much darker the shadow can be. Tau= 0.5 means that if a pixel is more than twice darker then it is not shadow. See Prati, Mikic, Trivedi and Cucchiara, Detecting Moving Shadows...*, IEEE PAMI,2003.

setShadowThreshold

public void setShadowThreshold(double threshold)

\brief Sets the shadow threshold