added tutorials for KCF tracker

modules/tracking/samples/tutorial_customizing_cn_tracker.cpp

@@ -0,0 +1,128 @@
+#include <opencv2/core/utility.hpp>
+#include <opencv2/tracking.hpp>
+#include <opencv2/videoio.hpp>
+#include <opencv2/highgui.hpp>
+#include <iostream>
+#include <cstring>
+
+using namespace std;
+using namespace cv;
+
+// prototype of the functino for feature extractor
+void sobelExtractor(const Mat img, const Rect roi, Mat& feat);
+
+int main( int argc, char** argv ){
+  // show help
+  if(argc<2){
+    cout<<
+      " Usage: tracker <video_name>\n"
+      " examples:\n"
+      " example_tracking_kcf Bolt/img/%04d.jpg\n"
+      " example_tracking_kcf faceocc2.webm\n"
+      << endl;
+    return 0;
+  }
+
+  // declares all required variables
+  Rect2d roi;
+  Mat frame;
+
+  //! [param]
+  TrackerKCF::Params param;
+  param.desc_pca = TrackerKCF::GRAY | TrackerKCF::CN;
+  param.desc_npca = 0;
+  param.compress_feature = true;
+  param.compressed_size = 2;
+  //! [param]
+
+  // create a tracker object
+  //! [create]
+  Ptr<TrackerKCF> tracker = TrackerKCF::createTracker(param);
+  //! [create]
+
+  //! [setextractor]
+  tracker->setFeatureExtractor(sobelExtractor);
+  //! [setextractor]
+
+  // set input video
+  std::string video = argv[1];
+  VideoCapture cap(video);
+
+  // get bounding box
+  cap >> frame;
+  roi=selectROI("tracker",frame);
+
+  //quit if ROI was not selected
+  if(roi.width==0 || roi.height==0)
+    return 0;
+
+  // initialize the tracker
+  tracker->init(frame,roi);
+
+  // perform the tracking process
+  printf("Start the tracking process, press ESC to quit.\n");
+  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
+    tracker->update(frame,roi);
+
+    // draw the tracked object
+    rectangle( frame, roi, Scalar( 255, 0, 0 ), 2, 1 );
+
+    // show image with the tracked object
+    imshow("tracker",frame);
+
+    //quit on ESC button
+    if(waitKey(1)==27)break;
+  }
+
+  return 0;
+}
+
+void sobelExtractor(const Mat img, const Rect roi, Mat& feat){
+    Mat sobel[2];
+    Mat patch;
+    Rect region=roi;
+
+    //! [insideimage]
+    // extract patch inside the image
+    if(roi.x<0){region.x=0;region.width+=roi.x;}
+    if(roi.y<0){region.y=0;region.height+=roi.y;}
+    if(roi.x+roi.width>img.cols)region.width=img.cols-roi.x;
+    if(roi.y+roi.height>img.rows)region.height=img.rows-roi.y;
+    if(region.width>img.cols)region.width=img.cols;
+    if(region.height>img.rows)region.height=img.rows;
+    //! [insideimage]
+
+    patch=img(region).clone();
+    cvtColor(patch,patch, CV_BGR2GRAY);
+
+    //! [padding]
+    // add some padding to compensate when the patch is outside image border
+    int addTop,addBottom, addLeft, addRight;
+    addTop=region.y-roi.y;
+    addBottom=(roi.height+roi.y>img.rows?roi.height+roi.y-img.rows:0);
+    addLeft=region.x-roi.x;
+    addRight=(roi.width+roi.x>img.cols?roi.width+roi.x-img.cols:0);
+
+    copyMakeBorder(patch,patch,addTop,addBottom,addLeft,addRight,BORDER_REPLICATE);
+    //! [padding]
+
+    //! [sobel]
+    Sobel(patch, sobel[0], CV_32F,1,0,1);
+    Sobel(patch, sobel[1], CV_32F,0,1,1);
+
+    merge(sobel,2,feat);
+    //! [sobel]
+
+    //! [postprocess]
+    feat.convertTo(feat,CV_64F);
+    feat=feat/255.0-0.5; // normalize to range -0.5 .. 0.5
+    //! [postprocess]
+}