tracking: add confidence threshold to TrackerKCF

modules/tracking/include/opencv2/tracking/tracker.hpp

@@ -1236,6 +1236,7 @@ class CV_EXPORTS_W TrackerKCF : public Tracker
     */
     void write(FileStorage& /*fs*/) const;
 
+    double detect_thresh;         //!<  detection confidence threshold
     double sigma;                 //!<  gaussian kernel bandwidth
     double lambda;                //!<  regularization
     double interp_factor;         //!<  linear interpolation factor for adaptation

modules/tracking/samples/kcf.cpp

@@ -13,29 +13,11 @@
 #include <opencv2/highgui.hpp>
 #include <iostream>
 #include <cstring>
+#include "samples_utility.hpp"
 
 using namespace std;
 using namespace cv;
 
-class BoxExtractor {
-public:
-  Rect2d extract(Mat img);
-  Rect2d extract(const std::string& windowName, Mat img, bool showCrossair = true);
-
-  struct handlerT{
-    bool isDrawing;
-    Rect2d box;
-    Mat image;
-
-    // initializer list
-    handlerT(): isDrawing(false) {};
-  }params;
-
-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 );
-};
-
 int main( int argc, char** argv ){
   // show help
   if(argc<2){
@@ -48,9 +30,6 @@ int main( int argc, char** argv ){
     return 0;
   }
 
-  // ROI selector
-  BoxExtractor box;
-
   // create the tracker
   Ptr<Tracker> tracker = TrackerKCF::create();
 
@@ -62,7 +41,7 @@ int main( int argc, char** argv ){
 
   // get bounding box
   cap >> frame;
-  Rect2d roi=box.extract("tracker",frame);
+  Rect2d roi= selectROI("tracker", frame, true, false);
 
   //quit if ROI was not selected
   if(roi.width==0 || roi.height==0)
@@ -82,7 +61,13 @@ int main( int argc, char** argv ){
       break;
 
     // update the tracking result
-    tracker->update(frame,roi);
+    bool isfound = tracker->update(frame,roi);
+    if(!isfound)
+    {
+        cout << "The target has been lost...\n";
+        waitKey(0);
+        return 0;
+    }
 
     // draw the tracked object
     rectangle( frame, roi, Scalar( 255, 0, 0 ), 2, 1 );
@@ -95,100 +80,3 @@ int main( int argc, char** argv ){
   }
 
 }
-
-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 ){
-          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 );
-      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::extract(Mat img){
-  return extract("Bounding Box Extractor", img);
-}
-
-Rect2d BoxExtractor::extract(const std::string& windowName, Mat img, bool showCrossair){
-
-  int key=0;
-
-  // show the image and give feedback to user
-  imshow(windowName,img);
-  printf("Select an object to track and then press SPACE/BACKSPACE/ENTER button!\n");
-
-  // 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;
-}

modules/tracking/src/trackerKCF.cpp

@@ -341,6 +341,10 @@ namespace cv{
 
       // extract the maximum response
       minMaxLoc( response, &minVal, &maxVal, &minLoc, &maxLoc );
+      if (maxVal < params.detect_thresh)
+      {
+          return false;
+      }
       roi.x+=(maxLoc.x-roi.width/2+1);
       roi.y+=(maxLoc.y-roi.height/2+1);
     }
@@ -821,6 +825,7 @@ namespace cv{
  * Parameters
  */
   TrackerKCF::Params::Params(){
+      detect_thresh = 0.5;
       sigma=0.2;
       lambda=0.01;
       interp_factor=0.075;
@@ -841,6 +846,9 @@ namespace cv{
   void TrackerKCF::Params::read( const cv::FileNode& fn ){
       *this = TrackerKCF::Params();
 
+      if (!fn["detect_thresh"].empty())
+          fn["detect_thresh"] >> detect_thresh;
+
       if (!fn["sigma"].empty())
           fn["sigma"] >> sigma;
 
@@ -883,6 +891,7 @@ namespace cv{
   }
 
   void TrackerKCF::Params::write( cv::FileStorage& fs ) const{
+    fs << "detect_thresh" << detect_thresh;
     fs << "sigma" << sigma;
     fs << "lambda" << lambda;
     fs << "interp_factor" << interp_factor;