Hi all, today I've finished the work on the shape merger. The algo works quite simple: 1) if two similar shapes (same type, name, min+max resolution) share one or more identical points, both are combined. In the combined shape, the longest sequence of identical points is removed. This reduces the number of points and the number of shapes. On the other hand, it makes shapes larger, so that it is more likely that many smaller landuse=forest shapes are combined and appear at lower resolution levels. 2) After merging, all points on (almost) straight lines are removed. This reduces again the img size and has a very nice side effect: Connected buildings look much better. Two screen shots show what I mean: Area in OSM: http://www.openstreetmap.org/node/21030850#map=17/53.06636/8.79033 Screenshots: http://files.mkgmap.org.uk/download/170/r2961.png http://files.mkgmap.org.uk/download/171/r2966_mergeshapes.png I see no big change in the runtime , I guess the additional cpu time that is needed for the merged is gained back because less data is written, the img size is 2-3% smaller compared to trunk. Any feedback is welcome. Gerd