<threshold map="diag5x5" alias="diag"> <description>Simple Diagonal Line Dither</description> <levels width="5" height="5" divisor="6"> 4 2 1 3 5 2 1 3 5 4 1 3 5 4 2 3 5 4 2 1 5 4 2 1 3 </levels> </threshold>