To better grasp the idea and avoid possible confusion, in this another example we have inverted the original image such as the object in white is now the letter. We have performed two dilatations with a rectangular structuring element of size :math:`3x3`.

.. image:: images/Morphology_1_Tutorial_Theory_Dilatation_2.png

:alt: Left image: original image inverted, right image: resulting dilatation

:align: center

The dilatation makes the object in white bigger.

In the same manner, the corresponding image resulting of the erosion operation on the inverted original image (two erosions with a rectangular structuring element of size :math:`3x3`.

.. image:: images/Morphology_1_Tutorial_Theory_Erosion_2.png

:alt: Left image: original image inverted, right image: resulting erosion

:align: center

The erosion makes the object in white smaller.

Based on these two we can effectuate more sophisticated transformations to our images. Here we discuss briefly 5 operations offered by OpenCV:

For the sake of clarity, we have performed the opening operation (:math:`7x7` rectangular structuring element) on the same original image but inverted such as the object in white is now the letter.

.. image:: images/Morphology_2_Tutorial_Theory_Opening_2.png

:alt: Left image: original image inverted, right image: resulting opening

:align: center

On the inverted image, we have performed the closing operation (:math:`7x7` rectangular structuring element):

.. image:: images/Morphology_2_Tutorial_Theory_Closing_2.png

:alt: Left image: original image inverted, right image: resulting closing

:align: center