added VIBE_GPU (background subtraction) to gpu module

modules/gpu/include/opencv2/gpu/gpu.hpp

@@ -1992,6 +1992,9 @@ public:
     //! computes a background image which are the mean of all background gaussians
     void getBackgroundImage(GpuMat& backgroundImage, Stream& stream = Stream::Null()) const;
 
+    //! releases all inner buffers
+    void release();
+
     int history;
     float varThreshold;
     float backgroundRatio;
@@ -2032,6 +2035,9 @@ public:
     //! computes a background image which are the mean of all background gaussians
     void getBackgroundImage(GpuMat& backgroundImage, Stream& stream = Stream::Null()) const;
 
+    //! releases all inner buffers
+    void release();
+
     // parameters
     // you should call initialize after parameters changes
 
@@ -2100,6 +2106,41 @@ private:
     GpuMat bgmodelUsedModes_; //keep track of number of modes per pixel
 };
 
+/*!
+ * The class implements the following algorithm:
+ * "ViBe: A universal background subtraction algorithm for video sequences"
+ * O. Barnich and M. Van D Roogenbroeck
+ * IEEE Transactions on Image Processing, 20(6) :1709-1724, June 2011
+ */
+class CV_EXPORTS VIBE_GPU
+{
+public:
+    //! the default constructor
+    explicit VIBE_GPU(unsigned long rngSeed = 1234567);
+
+    //! re-initiaization method
+    void initialize(const GpuMat& firstFrame, Stream& stream = Stream::Null());
+
+    //! the update operator
+    void operator()(const GpuMat& frame, GpuMat& fgmask, Stream& stream = Stream::Null());
+
+    //! releases all inner buffers
+    void release();
+
+    int nbSamples;         // number of samples per pixel
+    int reqMatches;        // #_min
+    int radius;            // R
+    int subsamplingFactor; // amount of random subsampling
+
+private:
+    Size frameSize_;
+
+    unsigned long rngSeed_;
+    GpuMat randStates_;
+
+    GpuMat samples_;
+};
+
 ////////////////////////////////// Video Encoding //////////////////////////////////
 
 // Works only under Windows