Running the Application
=======================

Graphical User Interface
------------------------

Tracker with the Graphical User Interface (GUI) can be started by
entering the following command into your Linux or Mac terminal, or into your
`Anaconda Prompt` on Windows::

  tracker

.. Note::
    On windows, the GUI can also be started by clicking on the desktop icon.

.. _no_gui:

Without the Graphical User Interface
------------------------------------

To facilitate batch processing and maximize performance, files can be processed
without the GUI. This can be done by passing the ``--nogui`` or ``-ng`` flag and
a path to a ``*.trak`` file::

  tracker -ng path/to/my/track/file/video1.trak

The path can contain unix wild cards that will be used to find ``*.trak``
files. To process all ``*.trak`` files in a directory, the following command can
be used::

  tracker -ng path/to/folder/with/track/files/*.trak

A list of paths can also be passed::

  tracker -ng path/to/*.trak otherpath/to/video1.trak

For more command line options, see :ref:`cmd_reference`

Parallelization
---------------

Both the GUI and no-GUI version can utilize parallelization to speed up the
processing. The number of workers and the parallelization method (multi-thread
or multi-processed) can be specified on the command line. To specify the number
of workers, use the ``-w N`` flag where ``N`` is an integer greater than 0. By
default, the application runs multi-thread. To use multi-processing, pass the
``-mp`` flag. As an example, to process a ``*.trak`` file using 4 workers and
multi-processing use::

  tracker -w 4 -mp path/to/video1.trak

Please refer to the :ref:`parallel_reference` for more information.

.. Warning::
    Multiprocessing on Windows does not work due to issues between python's
    multiprocessing library and OpenCV.