Without Graphical User Interface (No GUI)
=========================================

This tutorial shows how to run a previously setup ``*.trak`` file without
running the GUI. This allows for maximum performance because results do not
need to be sent back to the GUI and displayed. This also allows for processing
multiple ``*.trak`` files sequentially, minimizing downtime if you want to run
unattended.

Assuming that you have already followed one of the other tutorials or tried
tracking your own images, you need to have a ``.trak`` file to use in this
tutorial. The ``*.trak`` contains all the options set through the GUI,
including the path to the images to process and writing the output files.

Processing a single file
------------------------

To process a single ``*.trak`` file, open an Anaconda prompt, making sure to
activate the correct environment. We will pass the ``--nogui`` flag to tracker,
telling tracker to not open the GUI, and the path to your ``*.trak`` file::

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

You should then see the output similar to the following, indicating the number
of workers, the path to the ``*.trak`` file, and the current progress::

    Running in no gui mode...
    Starting 8 workers... Done.

    Processing: tracker\examples\1000_synthetic_hough_circles.trak
    Tracking / |â–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆâ–ˆ----------------------------| 41.4%

There are more command line options that can be used to control the processing,
such as the numbner of workers, start frame, end frame, etc.. To see the
available options, pass ``--help``. They are also listed here: :ref:`cmd_reference`.

Processing multiple files
-------------------------

The no GUI mode can also be used to process multiple files in series, either by
specifying individual paths to files, or by using wild cards. For example, you
can specify two paths to specific files::

    tracker --nogui videos/video1.trak videos/video2.trak

Or you can process all the ``*.trak`` files in a directory with::

    tracker --nogui videos/*.trak

Finally, if you wanted to process specific patterns of files in different
directories, you can specify multiple paths with wild cards::

    tracker --nogui test1/*.trak test2/lower_*.trak test2/middle_*.trak