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 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

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
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
Picture after the convolution filter