BackgroundSubtractorMOG2 Class |
The class implements the following algorithm:
"Improved adaptive Gaussian mixture model for background subtraction"
Z.Zivkovic
International Conference Pattern Recognition, UK, August, 2004.
http://www.zoranz.net/Publications/zivkovic2004ICPR.pdf
Inheritance HierarchyNamespace: Emgu.CV
Assembly: Emgu.CV.World (in Emgu.CV.World.dll) Version: 4.0.1.3373 (4.0.1.3373)
SyntaxThe BackgroundSubtractorMOG2 type exposes the following members.
Constructors| Name | Description | |
|---|---|---|
 | BackgroundSubtractorMOG2 |
Create an "Improved adaptive Gaussian mixture model for background subtraction".
|
Properties| Name | Description | |
|---|---|---|
 | AlgorithmPtr |
Pointer to the unmanaged Algorithm object
|
| BackgroundRatio |
If a foreground pixel keeps semi-constant value for about backgroundRatio * history frames, it's considered background and added to the model as a center of a new component. It corresponds to TB parameter in the paper.
|
| BackgroundSubtractorPtr |
Pointer to the unmanaged BackgroundSubtractor object
|
| ComplexityReductionThreshold |
The maximum variance
|
| DetectShadows |
If true, the algorithm detects shadows and marks them.
|
| History |
The number of last frames that affect the background model
|
| NMixtures |
The number of gaussian components in the background model
|
| Ptr |
Pointer to the unmanaged object
(Inherited from UnmanagedObject.) |
| ShadowThreshold |
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.
|
| ShadowValue |
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.
|
| VarInit |
Tg=3*3=9 is default. A smaller Tg value generates more components. A higher Tg value may result in a small number of components but they can grow too large.
|
| VarMax |
The minimum variance
|
| VarMin |
The initial variance of each gaussian component
|
| VarThreshold |
The main threshold on the squared Mahalanobis distance to decide if the sample is well described by the background model or not. Related to Cthr from the paper.
|
| VarThresholdGen |
The variance threshold for the pixel-model match used for new mixture component generation. Threshold for the squared Mahalanobis distance that helps decide when a sample is close to the existing components (corresponds to Tg in the paper). If a pixel is not close to any component, it is considered foreground or added as a new component. 3 sigma =%gt
|
Methods| Name | Description | |
|---|---|---|
| Dispose |
The dispose function that implements IDisposable interface
(Inherited from DisposableObject.) |
 | DisposeObject |
Release all the unmanaged memory associated with this background model.
(Overrides DisposableObjectDisposeObject.) |
| Equals | (Inherited from Object.) |
| Finalize |
Destructor
(Inherited from DisposableObject.) |
| GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
| GetType | Gets the type of the current instance. (Inherited from Object.) |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
| ReleaseManagedResources |
Release the managed resources. This function will be called during the disposal of the current object.
override ride this function if you need to call the Dispose() function on any managed IDisposable object created by the current object
(Inherited from DisposableObject.) |
| ToString | Returns a string that represents the current object. (Inherited from Object.) |
Fields| Name | Description | |
|---|---|---|
 | _ptr |
A pointer to the unmanaged object
(Inherited from UnmanagedObject.) |
Extension Methods| Name | Description | |
|---|---|---|
 | Apply |
Update the background model
(Defined by BackgroundSubtractorExtension.) |
| Clear |
Clear the algorithm
(Defined by AlgorithmExtensions.) |
| GetBackgroundImage |
Computes a background image.
(Defined by BackgroundSubtractorExtension.) |
| GetDefaultName |
Returns the algorithm string identifier.
This string is used as top level xml/yml node tag when the object is saved to a file or string.
(Defined by AlgorithmExtensions.) |
| IsEmpty |
Returns true if the Algorithm is empty. e.g. in the very beginning or after unsuccessful read.
(Defined by AlgorithmExtensions.) |
| Load |
Loads algorithm from the file
(Defined by AlgorithmExtensions.) |
| LoadFromString |
Loads algorithm from a String
(Defined by AlgorithmExtensions.) |
| Read |
Reads algorithm parameters from a file storage.
(Defined by AlgorithmExtensions.) |
| Save |
Save the algorithm to file
(Defined by AlgorithmExtensions.) |
| SaveToString |
Save the algorithm to a string
(Defined by AlgorithmExtensions.) |
| Write(FileStorage) | Overloaded.
Stores algorithm parameters in a file storage
(Defined by AlgorithmExtensions.) |
| Write(FileStorage, String) | Overloaded.
Stores algorithm parameters in a file storage
(Defined by AlgorithmExtensions.) |
See Also