This is the tutorial sample http://docs.opencv.org/3.1.0/d2/d0a/tutorial_introduction_to_tracker.html
And this is what I get .
christian@christian-desktop ~/C++_Programas/02 $ g++ Tracker_01.cpp -o tracker_01 Tracker_01.cpp: In function ‘int main(int, char**)’: Tracker_01.cpp:26:7: error: ‘Tracker’ was not declared in this scope Ptr<tracker> tracker = Tracker::create( "KCF" ); ^ Thanks in advance .