diff --git a/modules/tracking/include/opencv2/tracking/tracker.hpp b/modules/tracking/include/opencv2/tracking/tracker.hpp
index 94c832d95..8c755051a 100644
--- a/modules/tracking/include/opencv2/tracking/tracker.hpp
+++ b/modules/tracking/include/opencv2/tracking/tracker.hpp
@@ -1198,9 +1198,32 @@ class CV_EXPORTS_W TrackerTLD : public Tracker
 class CV_EXPORTS_W TrackerKCF : public Tracker
 {
  public:
+  /**
+   * \brief Feature type to be used in the tracking grayscale, colornames, compressed color-names
+   */
   enum MODE {GRAY, CN, CN2};
+
   struct CV_EXPORTS Params
   {
+    /**
+     * \brief Constructor
+     * \param sigma bandwidth of the gaussian kernel
+     * \param lambda regularization coefficient
+     * \param interp_factor inear interpolation factor for model updating
+     * \param output_sigma_factor spatial bandwidth (proportional to target)
+     * \param pca_learning_rate learning rate of the compression method
+     * \param resize activate the resize feature to improve the processing speed
+     * \param split_coeff split the training coefficients into two matrices
+     * \param wrap_kernel wrap around the kernel values
+     * \param compressFeature activate pca method to compress the features
+     * \param max_patch_size threshold for the ROI size
+     * \param compressed_size feature size after compression
+     * \param descriptor descriptor type
+     * The modes available now:
+    -   "GRAY" -- Use grayscale values as the feature
+    -   "CN" -- Color-names feature
+    -   "CN2" -- Compressed color-names feature
+     */
     Params();
 
     /**
@@ -1219,17 +1242,17 @@ class CV_EXPORTS_W TrackerKCF : public Tracker
     double output_sigma_factor;   //!<  spatial bandwidth (proportional to target)
     double pca_learning_rate;     //!<  compression learning rate
     bool resize;                  //!<  activate the resize feature to improve the processing speed
-    bool splitCoeff;              //!<  split the training coefficients into two matrices
-    bool wrapKernel;              //!<  wrap around the kernel values
-    bool compressFeature;         //!<  activate pca method to compress the features
+    bool split_coeff;             //!<  split the training coefficients into two matrices
+    bool wrap_kernel;             //!<  wrap around the kernel values
+    bool compress_feature;         //!<  activate pca method to compress the features
     int max_patch_size;           //!<  threshold for the ROI size
     int compressed_size;          //!<  feature size after compression
     MODE descriptor;              //!<  descriptor type
   };
 
   /** @brief Constructor
-    @param parameters KCF parameters TrackerKCF::Params
-     */
+      @param parameters KCF parameters TrackerKCF::Params
+  */
   BOILERPLATE_CODE("KCF",TrackerKCF);
 };
 
diff --git a/modules/tracking/samples/kcf.cpp b/modules/tracking/samples/kcf.cpp
index 7e0189507..2b403c695 100644
--- a/modules/tracking/samples/kcf.cpp
+++ b/modules/tracking/samples/kcf.cpp
@@ -1,6 +1,6 @@
 /*----------------------------------------------
  * Usage:
- * example_tracking_kcf <video path>
+ * example_tracking_kcf <video_name>
  *
  * example:
  * example_tracking_kcf Bolt/img/%04.jpg
@@ -13,7 +13,6 @@
 #include <opencv2/highgui.hpp>
 #include <iostream>
 #include <cstring>
-#include <algorithm>
 
 using namespace std;
 using namespace cv;
@@ -21,7 +20,7 @@ using namespace cv;
 class BoxExtractor {
 public:
   Rect2d extract(Mat img);
-  Rect2d extract(const std::string& windowName, Mat img);
+  Rect2d extract(const std::string& windowName, Mat img, bool showCrossair = true);
 
   struct handlerT{
     bool isDrawing;
@@ -37,25 +36,37 @@ private:
   void opencv_mouse_callback( int event, int x, int y, int , void *param );
 };
 
-int main( int , char** argv ){
+int main( int argc, char** argv ){
+  // show help
+  if(argc<2){
+    cout<<
+      " Usage: example_tracking_kcf <video_name>\n"
+      " examples:\n"
+      " example_tracking_kcf Bolt/img/%04.jpg\n"
+      " example_tracking_kcf faceocc2.webm\n"
+      << endl;
+    return 0;
+  }
+
+  // ROI selector
   BoxExtractor box;
 
   // create the tracker
   Ptr<Tracker> tracker = Tracker::create( "KCF" );
 
-  Rect2d roi;
-  int start_frame = 0;
+  // set input video
   std::string video = argv[1];
-
-  VideoCapture cap;
-  cap.open( video );
-  cap.set( CAP_PROP_POS_FRAMES, start_frame );
+  VideoCapture cap(video);
 
   Mat frame;
 
   // get bounding box
   cap >> frame;
-  roi=box.extract("tracker",frame);
+  Rect2d roi=box.extract("tracker",frame);
+
+  //quit if ROI was not selected
+  if(roi.width==0 || roi.height==0)
+    return 0;
 
   // initialize the tracker
   tracker->init(frame,roi);
@@ -126,7 +137,7 @@ Rect2d BoxExtractor::extract(Mat img){
   return extract("Bounding Box Extractor", img);
 }
 
-Rect2d BoxExtractor::extract(const std::string& windowName, Mat img){
+Rect2d BoxExtractor::extract(const std::string& windowName, Mat img, bool showCrossair){
 
   int key=0;
 
@@ -140,6 +151,7 @@ Rect2d BoxExtractor::extract(const std::string& windowName, Mat img){
   // 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(
@@ -148,6 +160,25 @@ Rect2d BoxExtractor::extract(const std::string& windowName, Mat img){
       Scalar(255,0,0),2,1
     );
 
+    // draw cross air in the middle of bounding box
+    if(showCrossair){
+      // horizontal line
+      line(
+        params.image,
+        Point(params.box.x,params.box.y+0.5*params.box.height),
+        Point(params.box.x+params.box.width,params.box.y+0.5*params.box.height),
+        Scalar(255,0,0),2,1
+      );
+
+      // vertical line
+      line(
+        params.image,
+        Point(params.box.x+0.5*params.box.width,params.box.y),
+        Point(params.box.x+0.5*params.box.width,params.box.y+params.box.height),
+        Scalar(255,0,0),2,1
+      );
+    }
+
     // show the image bouding box
     imshow(windowName,params.image);
 
@@ -160,4 +191,4 @@ Rect2d BoxExtractor::extract(const std::string& windowName, Mat img){
 
 
   return params.box;
-}
\ No newline at end of file
+}
diff --git a/modules/tracking/src/trackerKCF.cpp b/modules/tracking/src/trackerKCF.cpp
index 58b50014b..385bc8510 100644
--- a/modules/tracking/src/trackerKCF.cpp
+++ b/modules/tracking/src/trackerKCF.cpp
@@ -226,7 +226,7 @@ namespace cv{
     // detection part
     if(frame>0){
       //compute the gaussian kernel
-      if(params.compressFeature){
+      if(params.compress_feature){
         compress(proj_mtx,x,x);
         compress(proj_mtx,z,zc);
         denseGaussKernel(params.sigma,x,zc,k);
@@ -234,7 +234,7 @@ namespace cv{
         denseGaussKernel(params.sigma,x,z,k);
 
       // calculate filter response
-      if(params.splitCoeff)
+      if(params.split_coeff)
         calcResponse(alphaf,alphaf_den,k,response);
       else
         calcResponse(alphaf,k,response);
@@ -259,7 +259,7 @@ namespace cv{
     else
       z=(1.0-params.interp_factor)*z+params.interp_factor*new_z;
 
-    if(params.compressFeature){
+    if(params.compress_feature){
       // feature compression
       updateProjectionMatrix(z,old_cov_mtx,proj_mtx,params.pca_learning_rate,params.compressed_size);
       compress(proj_mtx,x,x);
@@ -278,7 +278,7 @@ namespace cv{
     new_alphaf=Mat_<Vec2d >(yf.rows, yf.cols);
     std::complex<double> temp;
 
-    if(params.splitCoeff){
+    if(params.split_coeff){
       mulSpectrums(yf,kf,new_alphaf,0);
       mulSpectrums(kf,kf_lambda,new_alphaf_den,0);
     }else{
@@ -294,10 +294,10 @@ namespace cv{
     // update the RLS model
     if(frame==0){
       alphaf=new_alphaf.clone();
-      if(params.splitCoeff)alphaf_den=new_alphaf_den.clone();
+      if(params.split_coeff)alphaf_den=new_alphaf_den.clone();
     }else{
       alphaf=(1.0-params.interp_factor)*alphaf+params.interp_factor*new_alphaf;
-      if(params.splitCoeff)alphaf_den=(1.0-params.interp_factor)*alphaf_den+params.interp_factor*new_alphaf_den;
+      if(params.split_coeff)alphaf_den=(1.0-params.interp_factor)*alphaf_den+params.interp_factor*new_alphaf_den;
     }
 
     frame++;
@@ -551,7 +551,7 @@ namespace cv{
     sumChannels(xyf_v,xyf);
     ifft2(xyf,xyf);
 
-    if(params.wrapKernel){
+    if(params.wrap_kernel){
       shiftRows(xyf, _x.rows/2);
       shiftCols(xyf, _x.cols/2);
     }
@@ -671,11 +671,11 @@ namespace cv{
       resize=true;
       max_patch_size=80*80;
       descriptor=CN;
-      splitCoeff=true;
-      wrapKernel=false;
+      split_coeff=true;
+      wrap_kernel=false;
 
       //feature compression
-      compressFeature=true;
+      compress_feature=true;
       compressed_size=2;
       pca_learning_rate=0.15;
   }