some more fixes in background/foreground subtraction; converted bgfg_segm.cpp sample to C++

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

@@ -419,7 +419,7 @@ public:
                                      double TB=0.9,
                                      double CT=0.05,
                                      
-                                     uchar shadowOutputValue=127,
+                                     int shadowOutputValue=127,
                                      double tau=0.5);
     
     //! the destructor
@@ -442,7 +442,7 @@ public:
                             double TB=0.9,
                             double CT=0.05,
                             
-                            uchar nShadowDetection=127,
+                            int nShadowDetection=127,
                             double tau=0.5);
     
     void* model;

modules/video/src/bgfg_gaussmix2.cpp

@@ -539,7 +539,7 @@ BackgroundSubtractorMOG2::BackgroundSubtractorMOG2()
 BackgroundSubtractorMOG2::BackgroundSubtractorMOG2(double alphaT,
     double sigma, int nmixtures, bool postFiltering, double minArea,
     bool detectShadows, bool removeForeground, double Tb, double Tg,
-    double TB, double CT, uchar shadowValue, double tau)
+    double TB, double CT, int shadowValue, double tau)
 {
     model = 0;
     initialize(Size(), alphaT, sigma, nmixtures, postFiltering, minArea,
@@ -550,7 +550,7 @@ BackgroundSubtractorMOG2::BackgroundSubtractorMOG2(double alphaT,
 void BackgroundSubtractorMOG2::initialize(Size frameSize, double alphaT,
     double sigma, int nmixtures, bool postFiltering, double minArea,
     bool detectShadows, bool removeForeground, double Tb, double Tg,
-    double TB, double CT, uchar shadowValue, double tau)
+    double TB, double CT, int shadowValue, double tau)
 {
     if(!model)
         model = new CvGaussBGModel2;
@@ -605,10 +605,10 @@ void BackgroundSubtractorMOG2::operator()(const Mat& image0, Mat& fgmask0, doubl
     CvGaussBGModel2* bg_model = (CvGaussBGModel2*)model;
     
     CV_Assert(bg_model != 0);
-    Mat fgmask = fgmask0, image = image0;
+    Mat image = image0, fgmask = fgmask0;
     CV_Assert( image.type() == CV_8UC1 || image.type() == CV_8UC3 );
     
-    if( learningRate <= 0 )
+    if( learningRate < 0 )
         learningRate = bg_model->params.fAlphaT;
     if( learningRate >= 1 )
     {
@@ -653,9 +653,8 @@ void BackgroundSubtractorMOG2::operator()(const Mat& image0, Mat& fgmask0, doubl
                      
     icvUpdatePixelBackgroundGMM(&bg_model->data,&bg_model->params,alpha,image.data,fgmask.data);
     
-	if (!bg_model->params.bPostFiltering)
-        return;
-
+	if( bg_model->params.bPostFiltering )
+    {
         //foreground filtering: filter out small regions    
         morphologyEx(fgmask, fgmask, CV_MOP_OPEN, Mat());
         morphologyEx(fgmask, fgmask, CV_MOP_CLOSE, Mat());
@@ -670,6 +669,7 @@ void BackgroundSubtractorMOG2::operator()(const Mat& image0, Mat& fgmask0, doubl
                 continue;
             drawContours(fgmask, contours, (int)i, Scalar::all(255), -1, 8, vector<Vec4i>(), 1);
         }
+    }
     
     fgmask.copyTo(fgmask0);
 }

samples/cpp/bgfg_segm.cpp

 #include <opencv2/video/background_segm.hpp>
 #include <opencv2/highgui/highgui.hpp>
-
 #include <stdio.h>
+
+using namespace cv;
+
 void help()
 {
  printf("\nDo background segmentation, especially demonstrating the use of cvUpdateBGStatModel().\n"
@@ -14,51 +16,39 @@ void help()
 //this is a sample for foreground detection functions
 int main(int argc, char** argv)
 {
-    IplImage*       tmp_frame = NULL;
-    CvCapture*      cap = NULL;
+    VideoCapture cap;
     bool update_bg_model = true;
 
     if( argc < 2 )
-        cap = cvCaptureFromCAM(0);
+        cap.open(0);
     else
-        cap = cvCaptureFromFile(argv[1]);
+        cap.open(argv[1]);
     help();
     
-    if( !cap )
+    if( !cap.isOpened() )
     {
         printf("can not open camera or video file\n");
         return -1;
     }
     
-    tmp_frame = cvQueryFrame(cap);
-    if(!tmp_frame)
-    {
-        printf("can not read data from the video source\n");
-        return -1;
-    }
-
-    cvNamedWindow("BG", 1);
-    cvNamedWindow("FG", 1);
+    namedWindow("BG", 1);
+    namedWindow("FG", 1);
 
-    CvBGStatModel* bg_model = 0;
+    BackgroundSubtractorMOG2 bg_model;
+    Mat img, fgmask;
     
-    for( int fr = 1;tmp_frame; tmp_frame = cvQueryFrame(cap), fr++ )
+    for(;;)
     {
-        if(!bg_model)
-        {
-            //create BG model
-            bg_model = cvCreateGaussianBGModel( tmp_frame );
-            //bg_model = cvCreateFGDStatModel( temp );
-            continue;
-        }
+        cap >> img;
+        
+        if( img.empty() )
+            break;
         
-        double t = (double)cvGetTickCount();
-        cvUpdateBGStatModel( tmp_frame, bg_model, update_bg_model ? -1 : 0 );
-        t = (double)cvGetTickCount() - t;
-        printf( "%d. %.1f\n", fr, t/(cvGetTickFrequency()*1000.) );
-        cvShowImage("BG", bg_model->background);
-        cvShowImage("FG", bg_model->foreground);
-        char k = cvWaitKey(5);
+        bg_model(img, fgmask, update_bg_model ? -1 : 0);
+        
+        imshow("image", img);
+        imshow("foreground mask", fgmask);
+        char k = (char)waitKey(30);
         if( k == 27 ) break;
         if( k == ' ' )
         {
@@ -70,9 +60,5 @@ int main(int argc, char** argv)
         }
     }
 
-
-    cvReleaseBGStatModel( &bg_model );
-    cvReleaseCapture(&cap);
-
     return 0;
 }