K-nearest neighbours - based Background/Foreground Segmentation Algorithm. More...

Public Member Functions
bool	getDetectShadows ()
	Returns the shadow detection flag.

double	getDist2Threshold ()
	Returns the threshold on the squared distance between the pixel and the sample.

int	getHistory ()
	Returns the number of last frames that affect the background model.

int	getkNNSamples ()
	Returns the number of neighbours, the k in the kNN.

int	getNSamples ()
	Returns the number of data samples in the background model.

double	getShadowThreshold ()
	Returns the shadow threshold.

int	getShadowValue ()
	Returns the shadow value.

void	setDetectShadows (bool detectShadows)
	Enables or disables shadow detection.

void	setDist2Threshold (double _dist2Threshold)
	Sets the threshold on the squared distance.

void	setHistory (int history)
	Sets the number of last frames that affect the background model.

void	setkNNSamples (int _nkNN)
	Sets the k in the kNN. How many nearest neighbours need to match.

void	setNSamples (int _nN)
	Sets the number of data samples in the background model.

void	setShadowThreshold (double threshold)
	Sets the shadow threshold.

void	setShadowValue (int value)
	Sets the shadow value.

Public Member Functions inherited from OpenCVForUnity.VideoModule.BackgroundSubtractor
virtual void	apply (Mat image, Mat fgmask)
	Computes a foreground mask.

virtual void	apply (Mat image, Mat fgmask, double learningRate)
	Computes a foreground mask.

virtual void	getBackgroundImage (Mat backgroundImage)
	Computes a background image.

Public Member Functions inherited from OpenCVForUnity.CoreModule.Algorithm
virtual void	clear ()
	Clears the algorithm state.

virtual bool	empty ()
	Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read.

virtual string	getDefaultName ()

IntPtr	getNativeObjAddr ()

void	save (string filename)

Public Member Functions inherited from OpenCVForUnity.DisposableObject
void	Dispose ()

void	ThrowIfDisposed ()

Static Public Member Functions
static new BackgroundSubtractorKNN	__fromPtr__ (IntPtr addr)

Static Public Member Functions inherited from OpenCVForUnity.VideoModule.BackgroundSubtractor
static new BackgroundSubtractor	__fromPtr__ (IntPtr addr)

Static Public Member Functions inherited from OpenCVForUnity.CoreModule.Algorithm
static Algorithm	__fromPtr__ (IntPtr addr)

Static Public Member Functions inherited from OpenCVForUnity.DisposableObject
static IntPtr	ThrowIfNullIntPtr (IntPtr ptr)

Protected Member Functions
override void	Dispose (bool disposing)

Protected Member Functions inherited from OpenCVForUnity.VideoModule.BackgroundSubtractor
Protected Member Functions inherited from OpenCVForUnity.CoreModule.Algorithm
Protected Member Functions inherited from OpenCVForUnity.DisposableOpenCVObject
	DisposableOpenCVObject ()

	DisposableOpenCVObject (bool isEnabledDispose)

	DisposableOpenCVObject (IntPtr ptr)

	DisposableOpenCVObject (IntPtr ptr, bool isEnabledDispose)

override void	Dispose (bool disposing)

Protected Member Functions inherited from OpenCVForUnity.DisposableObject
	DisposableObject ()

	DisposableObject (bool isEnabledDispose)

Additional Inherited Members
Package Functions inherited from OpenCVForUnity.VideoModule.BackgroundSubtractor
Package Functions inherited from OpenCVForUnity.CoreModule.Algorithm
Package Attributes inherited from OpenCVForUnity.DisposableOpenCVObject
Properties inherited from OpenCVForUnity.DisposableObject
bool	IsDisposed `[get, protected set]`

bool	IsEnabledDispose `[get, set]`

Detailed Description

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

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

Member Function Documentation

◆ fromPtr()

static new BackgroundSubtractorKNN OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.__fromPtr__ ( IntPtr addr )

static

◆ Dispose()

override void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.Dispose ( bool disposing )

protectedvirtual

Reimplemented from OpenCVForUnity.VideoModule.BackgroundSubtractor.

◆ getDetectShadows()

bool OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getDetectShadows ( )

Returns the shadow detection flag.

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

◆ getDist2Threshold()

double OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getDist2Threshold ( )

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.

◆ getHistory()

int OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getHistory ( )

Returns the number of last frames that affect the background model.

◆ getkNNSamples()

int OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getkNNSamples ( )

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.

◆ getNSamples()

int OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getNSamples ( )

Returns the number of data samples in the background model.

◆ getShadowThreshold()

double OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getShadowThreshold ( )

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.

◆ getShadowValue()

int OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.getShadowValue ( )

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.

◆ setDetectShadows()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setDetectShadows ( bool detectShadows )

Enables or disables shadow detection.

◆ setDist2Threshold()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setDist2Threshold ( double _dist2Threshold )

Sets the threshold on the squared distance.

◆ setHistory()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setHistory ( int history )

Sets the number of last frames that affect the background model.

◆ setkNNSamples()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setkNNSamples ( int _nkNN )

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

◆ setNSamples()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setNSamples ( int _nN )

Sets the number of data samples in the background model.

The model needs to be reinitalized to reserve memory.

◆ setShadowThreshold()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setShadowThreshold ( double threshold )

Sets the shadow threshold.

◆ setShadowValue()

void OpenCVForUnity.VideoModule.BackgroundSubtractorKNN.setShadowValue ( int value )

Sets the shadow value.

The documentation for this class was generated from the following file:

OpenCVForUnity/Assets/OpenCVForUnity/org/opencv/video/BackgroundSubtractorKNN.cs

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members