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127 lines
5.3 KiB
127 lines
5.3 KiB
Background Segmentation |
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.. highlight:: cpp |
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gpu::BackgroundSubtractorMOG |
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Gaussian Mixture-based Background/Foreground Segmentation Algorithm. |
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.. ocv:class:: gpu::BackgroundSubtractorMOG : public cv::BackgroundSubtractorMOG |
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The class discriminates between foreground and background pixels by building and maintaining a model of the background. Any pixel which does not fit this model is then deemed to be foreground. The class implements algorithm described in [MOG2001]_. |
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.. seealso:: :ocv:class:`BackgroundSubtractorMOG` |
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.. Sample code:: |
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* : An example on gaussian mixture based background/foreground segmantation can be found at opencv_source_code/samples/gpu/bgfg_segm.cpp |
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gpu::createBackgroundSubtractorMOG |
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Creates mixture-of-gaussian background subtractor |
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.. ocv:function:: Ptr<gpu::BackgroundSubtractorMOG> gpu::createBackgroundSubtractorMOG(int history=200, int nmixtures=5, double backgroundRatio=0.7, double noiseSigma=0) |
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:param history: Length of the history. |
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:param nmixtures: Number of Gaussian mixtures. |
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:param backgroundRatio: Background ratio. |
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:param noiseSigma: Noise strength (standard deviation of the brightness or each color channel). 0 means some automatic value. |
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gpu::BackgroundSubtractorMOG2 |
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----------------------------- |
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Gaussian Mixture-based Background/Foreground Segmentation Algorithm. |
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.. ocv:class:: gpu::BackgroundSubtractorMOG2 : public cv::BackgroundSubtractorMOG2 |
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The class discriminates between foreground and background pixels by building and maintaining a model of the background. Any pixel which does not fit this model is then deemed to be foreground. The class implements algorithm described in [MOG2004]_. |
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.. seealso:: :ocv:class:`BackgroundSubtractorMOG2` |
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gpu::createBackgroundSubtractorMOG2 |
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----------------------------------- |
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Creates MOG2 Background Subtractor |
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.. ocv:function:: Ptr<gpu::BackgroundSubtractorMOG2> gpu::createBackgroundSubtractorMOG2( int history=500, double varThreshold=16, bool detectShadows=true ) |
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:param history: Length of the history. |
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:param varThreshold: Threshold on the squared Mahalanobis distance between the pixel and the model to decide whether a pixel is well described by the background model. This parameter does not affect the background update. |
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:param detectShadows: If true, the algorithm will detect shadows and mark them. It decreases the speed a bit, so if you do not need this feature, set the parameter to false. |
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gpu::BackgroundSubtractorGMG |
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---------------------------- |
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Background/Foreground Segmentation Algorithm. |
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.. ocv:class:: gpu::BackgroundSubtractorGMG : public cv::BackgroundSubtractorGMG |
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The class discriminates between foreground and background pixels by building and maintaining a model of the background. Any pixel which does not fit this model is then deemed to be foreground. The class implements algorithm described in [GMG2012]_. |
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gpu::createBackgroundSubtractorGMG |
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---------------------------------- |
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Creates GMG Background Subtractor |
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.. ocv:function:: Ptr<gpu::BackgroundSubtractorGMG> gpu::createBackgroundSubtractorGMG(int initializationFrames = 120, double decisionThreshold = 0.8) |
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:param initializationFrames: Number of frames of video to use to initialize histograms. |
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:param decisionThreshold: Value above which pixel is determined to be FG. |
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gpu::BackgroundSubtractorFGD |
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---------------------------- |
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.. ocv:class:: gpu::BackgroundSubtractorFGD : public cv::BackgroundSubtractor |
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The class discriminates between foreground and background pixels by building and maintaining a model of the background. Any pixel which does not fit this model is then deemed to be foreground. The class implements algorithm described in [FGD2003]_. :: |
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class CV_EXPORTS BackgroundSubtractorFGD : public cv::BackgroundSubtractor |
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{ |
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public: |
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virtual void getForegroundRegions(OutputArrayOfArrays foreground_regions) = 0; |
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}; |
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.. seealso:: :ocv:class:`BackgroundSubtractor` |
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gpu::BackgroundSubtractorFGD::getForegroundRegions |
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-------------------------------------------------- |
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Returns the output foreground regions calculated by :ocv:func:`findContours`. |
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.. ocv:function:: void gpu::BackgroundSubtractorFGD::getForegroundRegions(OutputArrayOfArrays foreground_regions) |
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:params foreground_regions: Output array (CPU memory). |
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gpu::createBackgroundSubtractorFGD |
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---------------------------------- |
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Creates FGD Background Subtractor |
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.. ocv:function:: Ptr<gpu::BackgroundSubtractorGMG> gpu::createBackgroundSubtractorFGD(const FGDParams& params = FGDParams()) |
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:param params: Algorithm's parameters. See [FGD2003]_ for explanation. |
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.. [FGD2003] Liyuan Li, Weimin Huang, Irene Y.H. Gu, and Qi Tian. *Foreground Object Detection from Videos Containing Complex Background*. ACM MM2003 9p, 2003. |
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.. [MOG2001] P. KadewTraKuPong and R. Bowden. *An improved adaptive background mixture model for real-time tracking with shadow detection*. Proc. 2nd European Workshop on Advanced Video-Based Surveillance Systems, 2001 |
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.. [MOG2004] Z. Zivkovic. *Improved adaptive Gausian mixture model for background subtraction*. International Conference Pattern Recognition, UK, August, 2004 |
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.. [GMG2012] A. Godbehere, A. Matsukawa and K. Goldberg. *Visual Tracking of Human Visitors under Variable-Lighting Conditions for a Responsive Audio Art Installation*. American Control Conference, Montreal, June 2012
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