SVG Screen Filter Primitive


Inkscape users have requested a filter that simulates screening as found in print. Such "filters" are found in photo editing software such as Photoshop and Gimp. Four color processes can be simulated by processing each color channel separately.

Example from Gimp of Newspaper Filter


Take an image, layout a grid. For each cell in grid determine the average intensity of image. Draw a spot sized proportional to intensity.


Set cell size
Determines Lines Per Inch (LPI)
Set angle of grid
Necessary for multi-color processes to avoid Moiré patterns. Four color screening: CMYK: angles 15% 75% 0% 45%.
Select spot shape.
Could be a URL to a symbol. In PostScript/PDF printing, the spot shape changes depending on desired intensity to enable a smooth transition from all white to all black.
Set color
For multi-color processes. Could use symbol color.


A screening filter would be a nice addition to the SVG specification but by itself it may not cross the benefit to cost threshold. There are a few enhancements that could make it much more useful.


Size and probability:

8895 Dots

Probability only:

11434 points

Size and probability:

11427 points

Cartography Examples


Placement controlled by gradient


Placment controlled by filter (feMorphology + feGuassianBlur), 2702 points


Circular spots with random position and color shifts. 21958 spots:

Current filters primitives can achieve parallel effects to pointillism. Inkscape has a number of built in filters such as the "Point engraving" filter which consists of 13 filter primitives: