Added: multitracker example

modules/tracking/samples/multitracker.cpp

+/*----------------------------------------------
+ * Usage:
+ * example_tracking_multitracker <video_name> [algorithm
+ *
+ * example:
+ * example_tracking_multitracker Bolt/img/%04.jpg
+ * example_tracking_multitracker faceocc2.webm KCF
+ *--------------------------------------------------*/
+
+#include <opencv2/core/utility.hpp>
+#include <opencv2/tracking.hpp>
+#include <opencv2/videoio.hpp>
+#include <opencv2/highgui.hpp>
+#include <iostream>
+#include <cstring>
+#include <ctime>
+
+#define RESET   "\033[0m"
+#define RED     "\033[31m"      /* Red */
+#define GREEN   "\033[32m"      /* Green */
+
+using namespace std;
+using namespace cv;
+
+class BoxExtractor {
+public:
+  Rect2d selectROI(Mat img, bool fromCenter = true);
+  Rect2d selectROI(const std::string& windowName, Mat img, bool showCrossair = true, bool fromCenter = true);
+  void selectROI(const std::string& windowName, Mat img, std::vector<Rect2d> & boundingBox, bool fromCenter = true);
+
+  struct handlerT{
+    // basic parameters
+    bool isDrawing;
+    Rect2d box;
+    Mat image;
+
+    // parameters for drawing from the center
+    bool drawFromCenter;
+    Point2f center;
+
+    // initializer list
+    handlerT(): isDrawing(false), drawFromCenter(true) {};
+  }params;
+
+  // to store the tracked objects
+  vector<handlerT> objects;
+
+private:
+  static void mouseHandler(int event, int x, int y, int flags, void *param);
+  void opencv_mouse_callback( int event, int x, int y, int , void *param );
+
+  // save the keypressed characted
+  int key;
+};
+
+int main( int argc, char** argv ){
+  // show help
+  if(argc<2){
+    cout<<
+      " Usage: example_tracking_multitracker <video_name> [algorithm]\n"
+      " examples:\n"
+      " example_tracking_multitracker Bolt/img/%04.jpg\n"
+      " example_tracking_multitracker faceocc2.webm MEDIANFLOW\n"
+      << endl;
+    return 0;
+  }
+
+  // timer
+  clock_t timer;
+
+  // for showing the speed
+  double fps;
+  std::string text;
+  char buffer [50];
+
+  // ROI selector
+  BoxExtractor box;
+
+  // set the default tracking algorithm
+  std::string trackingAlg = "KCF";
+
+  // set the tracking algorithm from parameter
+  if(argc>2)
+    trackingAlg = argv[2];
+
+  // create the tracker
+  MultiTracker trackers(trackingAlg);
+
+  // container of the tracked objects
+  vector<Rect2d> objects;
+
+  // set input video
+  std::string video = argv[1];
+  VideoCapture cap(video);
+
+  Mat frame;
+
+  // get bounding box
+  cap >> frame;
+  box.selectROI("tracker",frame,objects);
+
+  //quit when the tracked object(s) is not provided
+  if(objects.size()<1)
+    return 0;
+
+  // initialize the tracker
+  trackers.add(frame,objects);
+
+  // do the tracking
+  printf(GREEN "Start the tracking process, press ESC to quit.\n" RESET);
+  for ( ;; ){
+    // get frame from the video
+    cap >> frame;
+
+    // stop the program if no more images
+    if(frame.rows==0 || frame.cols==0)
+      break;
+
+    // update the tracking result
+    timer=clock();
+    trackers.update(frame);
+    timer=clock()-timer;
+    fps=(double)CLOCKS_PER_SEC/(double)timer;
+
+    // draw the tracked object
+    for(unsigned i=0;i<trackers.objects.size();i++)
+    rectangle( frame, trackers.objects[i], Scalar( 255, 0, 0 ), 2, 1 );
+
+    // draw the processing speed
+    sprintf (buffer, "speed: %.02f fps", fps);
+    text = buffer;
+    putText(frame, text, Point(20,20), FONT_HERSHEY_PLAIN, 1, Scalar(255,255,255));
+
+    // show image with the tracked object
+    imshow("tracker",frame);
+
+    //quit on ESC button
+    if(waitKey(1)==27)break;
+  }
+
+}
+
+void BoxExtractor::mouseHandler(int event, int x, int y, int flags, void *param){
+    BoxExtractor *self =static_cast<BoxExtractor*>(param);
+    self->opencv_mouse_callback(event,x,y,flags,param);
+}
+
+void BoxExtractor::opencv_mouse_callback( int event, int x, int y, int , void *param ){
+    handlerT * data = (handlerT*)param;
+    switch( event ){
+      // update the selected bounding box
+      case EVENT_MOUSEMOVE:
+        if( data->isDrawing ){
+          if(data->drawFromCenter){
+            data->box.width = 2*(x-data->center.x)/*data->box.x*/;
+            data->box.height = 2*(y-data->center.y)/*data->box.y*/;
+            data->box.x = data->center.x-data->box.width/2.0;
+            data->box.y = data->center.y-data->box.height/2.0;
+          }else{
+            data->box.width = x-data->box.x;
+            data->box.height = y-data->box.y;
+          }
+        }
+      break;
+
+      // start to select the bounding box
+      case EVENT_LBUTTONDOWN:
+        data->isDrawing = true;
+        data->box = cvRect( x, y, 0, 0 );
+        data->center = Point2f(x,y);
+      break;
+
+      // cleaning up the selected bounding box
+      case EVENT_LBUTTONUP:
+        data->isDrawing = false;
+        if( data->box.width < 0 ){
+          data->box.x += data->box.width;
+          data->box.width *= -1;
+        }
+        if( data->box.height < 0 ){
+          data->box.y += data->box.height;
+          data->box.height *= -1;
+        }
+      break;
+    }
+}
+
+Rect2d BoxExtractor::selectROI(Mat img, bool fromCenter){
+  return selectROI("Bounding Box Extractor", img, fromCenter);
+}
+
+Rect2d BoxExtractor::selectROI(const std::string& windowName, Mat img, bool showCrossair, bool fromCenter){
+
+  key=0;
+
+  // set the drawing mode
+  params.drawFromCenter = fromCenter;
+
+  // show the image and give feedback to user
+  imshow(windowName,img);
+
+  // copy the data, rectangle should be drawn in the fresh image
+  params.image=img.clone();
+
+  // select the object
+  setMouseCallback( windowName, mouseHandler, (void *)&params );
+
+  // end selection process on SPACE (32) BACKSPACE (27) or ENTER (13)
+  while(!(key==32 || key==27 || key==13)){
+    // draw the selected object
+    rectangle(
+      params.image,
+      params.box,
+      Scalar(255,0,0),2,1
+    );
+
+    // draw cross air in the middle of bounding box
+    if(showCrossair){
+      // horizontal line
+      line(
+        params.image,
+        Point((int)params.box.x,(int)(params.box.y+params.box.height/2)),
+        Point((int)(params.box.x+params.box.width),(int)(params.box.y+params.box.height/2)),
+        Scalar(255,0,0),2,1
+      );
+
+      // vertical line
+      line(
+        params.image,
+        Point((int)(params.box.x+params.box.width/2),(int)params.box.y),
+        Point((int)(params.box.x+params.box.width/2),(int)(params.box.y+params.box.height)),
+        Scalar(255,0,0),2,1
+      );
+    }
+
+    // show the image bouding box
+    imshow(windowName,params.image);
+
+    // reset the image
+    params.image=img.clone();
+
+    //get keyboard event
+    key=waitKey(1);
+  }
+
+
+  return params.box;
+}
+
+void BoxExtractor::selectROI(const std::string& windowName, Mat img, std::vector<Rect2d> & boundingBox, bool fromCenter){
+  vector<Rect2d> box;
+  Rect2d temp;
+  key=0;
+
+  // show notice to user
+  printf(RED "Select an object to track and then press SPACE or ENTER button!\n" RESET);
+  printf(RED "Finish the selection process by pressing BACKSPACE button!\n" RESET);
+
+  // while key is not Backspace
+  while(key!=27){
+    temp=selectROI(windowName, img, true, fromCenter);
+    if(temp.width>0 && temp.height>0)
+      box.push_back(temp);
+  }
+  boundingBox=box;
+}
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