roslauch tracking kcf_tracker.launch
This node requires opencv/opencv_contrib >=3.3.1
The default for ros melodic is 3.2, you need to build the right version from source.
Kinetic defaults to 3.3.1, so I recommend that.
git clone https://github.com/opencv/opencv_contrib.git
cd opencv_contrib
git checkout -b v3.3.1 3.3.1`
git clone https://github.com/opencv/opencv.git
cd opencv
git checkout -b v3.3.1 3.3.1
mkdir build; cd build
cmake -DBUILD_opencv_cudacodec=OFF -D CMAKE_INSTALL_PREFIX=/usr/local -D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib/modules ..
make -j$(nproc)
`make install