Animation of the filter element
filterRes animated discrete within 60s and is frozen. It is changed with the values
0.5;1 1;2 2;3 3;4 4;5 5;6 6;7 7;8 8;9 9;10 10;11 11;12 12;8 4;2 4;4 2;4.2 4.8.
The filter is applied to a chequered blue area with 16 squares.
This raster is indicated black stroked for comparison. For a filterRes of 4, 8 or 12 (etc)
the filtered pattern has to fit exactly into the raster, for other filterRes there have to
be artifacts from the non fitting resolution. Due to the symmetries of the chequer pattern
the filterRes 0.5, 1, 2, 2 4, 4 2 etc have to result in only one color (the same for all) for the
complete area.
Gray rectangles top left indicate the size of one filter unit corresponding to the filterRes.
Note, that the specification does not require positive integers as values, only numbers.