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) `__ for details on the process. Edge pixels are always extended outside the image area. Arguments --------- - ``matrix_items`` - Semicolon separated integer or decimal matrix items. Decimal values must include digits after the decimal point, e.g. ``1.5``. - ``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