fixed warnings; added read/write methods; fixed docs

modules/video/include/opencv2/video/background_segm.hpp

@@ -59,7 +59,7 @@ class BackgroundSubtractor : public Algorithm
 {
 public:
     //! the update operator that takes the next video frame and returns the current foreground mask as 8-bit binary image.
-    virtual void apply(InputArray image, OutputArray fgmask, double learningRate=0) = 0;
+    virtual void apply(InputArray image, OutputArray fgmask, double learningRate=-1) = 0;
 
     //! computes a background image
     virtual void getBackgroundImage(OutputArray backgroundImage) const = 0;

modules/video/src/bgfg_gaussmix.cpp

@@ -82,6 +82,7 @@ public:
         varThreshold = defaultVarThreshold;
         backgroundRatio = defaultBackgroundRatio;
         noiseSigma = defaultNoiseSigma;
+        name_ = "BackgroundSubtractor.MOG";
     }
     // the full constructor that takes the length of the history,
     // the number of gaussian mixtures, the background ratio parameter and the noise strength
@@ -138,6 +139,24 @@ public:
     virtual double getNoiseSigma() const { return noiseSigma; }
     virtual void setNoiseSigma(double _noiseSigma) { noiseSigma = _noiseSigma; }
 
+    virtual void write(FileStorage& fs) const
+    {
+        fs << "name" << name_
+           << "history" << history
+           << "nmixtures" << nmixtures
+           << "backgroundRatio" << backgroundRatio
+           << "noiseSigma" << noiseSigma;
+    }
+
+    virtual void read(const FileNode& fn)
+    {
+        CV_Assert( (std::string)fn["name"] == name_ );
+        history = (int)fn["history"];
+        nmixtures = (int)fn["nmixtures"];
+        backgroundRatio = (double)fn["backgroundRatio"];
+        noiseSigma = (double)fn["noiseSigma"];
+    }
+
 protected:
     Size frameSize;
     int frameType;
@@ -148,6 +167,7 @@ protected:
     double varThreshold;
     double backgroundRatio;
     double noiseSigma;
+    std::string name_;
 };
 
 

modules/video/src/bgfg_gaussmix2.cpp

@@ -117,7 +117,7 @@ static const unsigned char defaultnShadowDetection2 = (unsigned char)127; // val
 static const float defaultfTau = 0.5f; // Tau - shadow threshold, see the paper for explanation
 
 
-class CV_EXPORTS BackgroundSubtractorMOG2Impl : public BackgroundSubtractorMOG2
+class BackgroundSubtractorMOG2Impl : public BackgroundSubtractorMOG2
 {
 public:
     //! the default constructor
@@ -164,6 +164,7 @@ public:
         fCT = defaultfCT2;
         nShadowDetection =  defaultnShadowDetection2;
         fTau = defaultfTau;
+        name_ = "BackgroundSubtractor.MOG2";
     }
     //! the destructor
     ~BackgroundSubtractorMOG2Impl() {}
@@ -231,6 +232,40 @@ public:
     virtual double getShadowThreshold() const { return fTau; }
     virtual void setShadowThreshold(double value) { fTau = (float)value; }
 
+    virtual void write(FileStorage& fs) const
+    {
+        fs << "name" << name_
+        << "history" << history
+        << "nmixtures" << nmixtures
+        << "backgroundRatio" << backgroundRatio
+        << "varThreshold" << varThreshold
+        << "varThresholdGen" << varThresholdGen
+        << "varInit" << fVarInit
+        << "varMin" << fVarMin
+        << "varMax" << fVarMax
+        << "complexityReductionThreshold" << fCT
+        << "detectShadows" << (int)bShadowDetection
+        << "shadowValue" << nShadowDetection
+        << "shadowThreshold" << fTau;
+    }
+
+    virtual void read(const FileNode& fn)
+    {
+        CV_Assert( (std::string)fn["name"] == name_ );
+        history = (int)fn["history"];
+        nmixtures = (int)fn["nmixtures"];
+        backgroundRatio = (float)fn["backgroundRatio"];
+        varThreshold = (double)fn["varThreshold"];
+        varThresholdGen = (float)fn["varThresholdGen"];
+        fVarInit = (float)fn["varInit"];
+        fVarMin = (float)fn["varMin"];
+        fVarMax = (float)fn["varMax"];
+        fCT = (float)fn["complexityReductionThreshold"];
+        bShadowDetection = (int)fn["detectShadows"] != 0;
+        nShadowDetection = (int)fn["shadowValue"];
+        fTau = (float)fn["shadowThreshold"];
+    }
+
 protected:
     Size frameSize;
     int frameType;
@@ -284,6 +319,8 @@ protected:
     //version of the background. Tau is a threshold on how much darker the shadow can be.
     //Tau= 0.5 means that if pixel is more than 2 times darker then it is not shadow
     //See: Prati,Mikic,Trivedi,Cucchiarra,"Detecting Moving Shadows...",IEEE PAMI,2003.
+
+    std::string name_;
 };
 
 struct GaussBGStatModel2Params

modules/video/src/bgfg_gmg.cpp

@@ -53,11 +53,30 @@
 namespace cv
 {
 
-class CV_EXPORTS BackgroundSubtractorGMGImpl : public BackgroundSubtractorGMG
+class BackgroundSubtractorGMGImpl : public BackgroundSubtractorGMG
 {
 public:
-    BackgroundSubtractorGMGImpl();
-    ~BackgroundSubtractorGMGImpl();
+    BackgroundSubtractorGMGImpl()
+    {
+        /*
+         * Default Parameter Values. Override with algorithm "set" method.
+         */
+        maxFeatures = 64;
+        learningRate = 0.025;
+        numInitializationFrames = 120;
+        quantizationLevels = 16;
+        backgroundPrior = 0.8;
+        decisionThreshold = 0.8;
+        smoothingRadius = 7;
+        updateBackgroundModel = true;
+        minVal_ = maxVal_ = 0;
+        name_ = "BackgroundSubtractor.GMG";
+    }
+    
+    ~BackgroundSubtractorGMGImpl()
+    {
+    }
+
     virtual AlgorithmInfo* info() const { return 0; }
 
     /**
@@ -117,6 +136,35 @@ public:
         CV_Error( CV_StsNotImplemented, "" );
     }
 
+    virtual void write(FileStorage& fs) const
+    {
+        fs << "name" << name_
+        << "maxFeatures" << maxFeatures
+        << "defaultLearningRate" << learningRate
+        << "numFrames" << numInitializationFrames
+        << "quantizationLevels" << quantizationLevels
+        << "backgroundPrior" << backgroundPrior
+        << "decisionThreshold" << decisionThreshold
+        << "smoothingRadius" << smoothingRadius
+        << "updateBackgroundModel" << (int)updateBackgroundModel;
+        // we do not save minVal_ & maxVal_, since they depend on the image type.
+    }
+
+    virtual void read(const FileNode& fn)
+    {
+        CV_Assert( (std::string)fn["name"] == name_ );
+        maxFeatures = (int)fn["maxFeatures"];
+        learningRate = (double)fn["defaultLearningRate"];
+        numInitializationFrames = (int)fn["numFrames"];
+        quantizationLevels = (int)fn["quantizationLevels"];
+        backgroundPrior = (double)fn["backgroundPrior"];
+        smoothingRadius = (int)fn["smoothingRadius"];
+        decisionThreshold = (double)fn["decisionThreshold"];
+        updateBackgroundModel = (int)fn["updateBackgroundModel"] != 0;
+        minVal_ = maxVal_ = 0;
+        frameSize_ = Size();
+    }
+
     //! Total number of distinct colors to maintain in histogram.
     int     maxFeatures;
     //! Set between 0.0 and 1.0, determines how quickly features are "forgotten" from histograms.
@@ -141,6 +189,8 @@ private:
     Size frameSize_;
     int frameNum_;
 
+    std::string name_;
+
     Mat_<int> nfeatures_;
     Mat_<unsigned int> colors_;
     Mat_<float> weights_;
@@ -148,25 +198,6 @@ private:
     Mat buf_;
 };
 
-BackgroundSubtractorGMGImpl::BackgroundSubtractorGMGImpl()
-{
-    /*
-     * Default Parameter Values. Override with algorithm "set" method.
-     */
-    maxFeatures = 64;
-    learningRate = 0.025;
-    numInitializationFrames = 120;
-    quantizationLevels = 16;
-    backgroundPrior = 0.8;
-    decisionThreshold = 0.8;
-    smoothingRadius = 7;
-    updateBackgroundModel = true;
-    minVal_ = maxVal_ = 0;
-}
-
-BackgroundSubtractorGMGImpl::~BackgroundSubtractorGMGImpl()
-{
-}
 
 void BackgroundSubtractorGMGImpl::initialize(Size frameSize, double minVal, double maxVal)
 {