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Convolution
===========
Usage: `convolution(matrix\_items, number\_of\_columns, should\_normalize)`
Description
-----------
This filter runs a convolution matrix (or kernel) on the image. See
`Kernel (image
processing) <http://en.wikipedia.org/wiki/Kernel_(image_processing)>`__
for details on the process. Edge pixels are always extended outside the
image area.
Arguments
---------
- ``matrix_items`` - Semicolon separated matrix items.
- ``number_of_columns`` - Number of columns in the matrix.
- ``should_normalize`` - Whether or not we should divide each matrix item by the sum of all items.
Example
-------
.. image:: images/tom_before_brightness.jpg
:alt: Picture before the convolution filter
Normalized Matrix:
::
1 2 1
2 4 2
2 1 2
::
http://localhost:8888/unsafe/filters:convolution(1;2;1;2;4;2;1;2;1,3,true)/http://upload.wikimedia.org/wikipedia/commons/5/50/Vd-Orig.png
.. image:: images/tom_after_convolution1.jpg
:alt: Picture after the convolution filter
Matrix:
::
-1 -1 -1
-1 8 -1
-1 -1 -1
::
http://localhost:8888/unsafe/filters:convolution(-1;-1;-1;-1;8;-1;-1;-1;-1,3,false)/http://upload.wikimedia.org/wikipedia/commons/5/50/Vd-Orig.png
.. image:: images/tom_after_convolution2.jpg
:alt: Picture after the convolution filter
|
