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

    Click :ref:`here <sphx_glr_download_advanced_image_processing_auto_examples_plot_propagation.py>` to download the full example code
.. rst-class:: sphx-glr-example-title

.. _sphx_glr_advanced_image_processing_auto_examples_plot_propagation.py:


Opening, erosion, and propagation
==================================

This example shows simple operations of mathematical morphology.




.. image:: /advanced/image_processing/auto_examples/images/sphx_glr_plot_propagation_001.png
    :class: sphx-glr-single-img





.. code-block:: python


    import numpy as np
    from scipy import ndimage
    import matplotlib.pyplot as plt

    square = np.zeros((32, 32))
    square[10:-10, 10:-10] = 1
    np.random.seed(2)
    x, y = (32*np.random.random((2, 20))).astype(np.int)
    square[x, y] = 1

    open_square = ndimage.binary_opening(square)

    eroded_square = ndimage.binary_erosion(square)
    reconstruction = ndimage.binary_propagation(eroded_square, mask=square)

    plt.figure(figsize=(9.5, 3))
    plt.subplot(131)
    plt.imshow(square, cmap=plt.cm.gray, interpolation='nearest')
    plt.axis('off')
    plt.subplot(132)
    plt.imshow(open_square, cmap=plt.cm.gray, interpolation='nearest')
    plt.axis('off')
    plt.subplot(133)
    plt.imshow(reconstruction, cmap=plt.cm.gray, interpolation='nearest')
    plt.axis('off')

    plt.subplots_adjust(wspace=0, hspace=0.02, top=0.99, bottom=0.01, left=0.01, right=0.99)
    plt.show()



**Total running time of the script:** ( 0 minutes  0.030 seconds)


.. _sphx_glr_download_advanced_image_processing_auto_examples_plot_propagation.py:


.. only :: html

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



  .. container:: sphx-glr-download

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



  .. container:: sphx-glr-download

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


.. only:: html

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

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