.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/introduction/demo_example.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        Click :ref:`here <sphx_glr_download_auto_examples_introduction_demo_example.py>`
        to download the full example code

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_auto_examples_introduction_demo_example.py:


=======================================
 Using the motion energy pyramid class
=======================================

This example shows how to extract motion energy features from a video.

First, we need to define the video we want to use. In this example, we'll use a small video. The video is 2.5 minutes in duration with a frame rate of 24fps. For the purposes of this example, we'll only use the first 200 frames.

.. GENERATED FROM PYTHON SOURCE LINES 10-15

.. code-block:: default


    nimages = 200
    stimulus_fps = 24
    video_file = 'http://anwarnunez.github.io/downloads/avsnr150s24fps_tiny.mp4'








.. GENERATED FROM PYTHON SOURCE LINES 16-22

.. raw:: html

   <video width=100% height=100% preload=none muted controls>
    <source src="https://anwarnunez.github.io/downloads/avsnr150s24fps_tiny.mp4" type="video/mp4">
   </video>


.. GENERATED FROM PYTHON SOURCE LINES 24-25

The video is RGB. So, the first step is to convert it to a luminance representation. Internally, this is achieved by converting RGB pixel values to CIE-LAB pixel values and keeping only the "L" channel. The function :func:`moten.io.video2luminance` takes care of downloading the video, converting RGB to luminance, and spatial downsampling if needed.

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.. code-block:: default


    import moten
    import matplotlib.pyplot as plt
    luminance_images = moten.io.video2luminance(video_file, nimages=nimages)
    nimages, vdim, hdim = luminance_images.shape





.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    /home/travis/virtualenv/python3.7.1/lib/python3.7/site-packages/scipy/__init__.py:137: UserWarning: NumPy 1.16.5 or above is required for this version of SciPy (detected version 1.16.4)
      UserWarning)




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Next we need to construct the motion energy pyramid. To achieve this, we must provide the size of the stimulus frames in pixels (``vdim`` and ``hdim``) and also the frame rate

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.. code-block:: default


    pyramid = moten.pyramids.MotionEnergyPyramid(stimulus_vhsize=(vdim, hdim),
                                                 stimulus_fps=stimulus_fps)

    print(pyramid)





.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    <moten.pyramids.MotionEnergyPyramid [#2530 filters (ntfq=3, nsfq=5, ndirs=8) aspect=1.778]>




.. GENERATED FROM PYTHON SOURCE LINES 40-41

Finally, we use the method ``project_stimulus`` to compute the motion energy features (see :meth:`moten.pyramids.MotionEnergyPyramid.project_stimulus`).

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.. code-block:: default


    features = pyramid.project_stimulus(luminance_images)
    print(features.shape)
    fig, ax = plt.subplots(figsize=(12, 12))
    ax.matshow(features, aspect='auto')
    plt.show()



.. image:: /auto_examples/introduction/images/sphx_glr_demo_example_001.png
    :alt: demo example
    :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    (200, 2530)





.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  42.264 seconds)


.. _sphx_glr_download_auto_examples_introduction_demo_example.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example



  .. container:: sphx-glr-download sphx-glr-download-python

     :download:`Download Python source code: demo_example.py <demo_example.py>`



  .. container:: sphx-glr-download sphx-glr-download-jupyter

     :download:`Download Jupyter notebook: demo_example.ipynb <demo_example.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_