The salt-dots pattern is based on salt-dots.svg

For the pattern visit [jsdotpattern (command sequence is recorded)](http://www.imagico.de/map/jsdotpattern.php#x,256,jdp68152;g,5,32,32;rx,25,2,32,32;rx,25,2,32,32;rx,25,2,32,32;rd,0,0,0,dot,0.125,10,9,0,jdp48264,ffffff,cdebb0;)

The result is this following [pattern](http://www.imagico.de/map/jsdotpattern.php#x,256,jdp68152;g,5,32,32;rx,25,2,32,32;rx,25,2,32,32;rx,25,2,32,32;rd,0,0,0,dot,0.125,10,9,0,jdp48264,ffffff,cdebb0;).

Generated SVG image is sanitized for use with Mapnik by the script svg_pattern.sh from the jsdotpattern repository at http://github.com/imagico/jsdotpattern.

The final file is salt-dots.svg

However, since SVG patterns is not properly handled by Mapnik at this time, the SVG file was converted to a PNG file with alpha channel, salt-dots.png
