Hi! As a result of conversion *.MP* to *.IMG* with *Mkgmap* (java -jar mkgmap.jar --mapname=12345678 --family-id=1281 --product-id=1 "AmericanLake.mp"), clearly expressed artifacts appear in the resulting map: <https://b.radikal.ru/b07/1902/89/31a7f4de23d0.png> If convert the same .MP-file using *cGPSmapper.exe*, such artifacts do not appear: <https://b.radikal.ru/b25/1902/62/de23809b837d.png> I suspect the reason is rather in the source .MP file: * Multipolygons consist of several hundred points. * The GPSMapEdit program finds intersections and overlays of polygons: http://b.radikal.ru/b29/1902/34/8177994b7e98.png * In addition, after converting multipolygons to polygons (deleting internal polygons from the file used), the artifacts disappear. But it is impossible to use a map (some objects such as islands and hills disappear) obtained in this way: <https://a.radikal.ru/a42/1902/94/0b9aeffc449e.png> However, despite possible problems with the source file, *cGPSmapper.exe converts it without any problems* !!! Is there a way to get *Mkgmap* to convert this file ? Maybe there are some "secret" command line parameters ? I tried unsuccessfully these arguments: --reduce-point-density= --reduce-point-density-polygon= --order-by-decreasing-area ... Generalization in GpsMapEdit not helped... Original *.MP* file posted here: https://yadi.sk/d/c5-7lv8v-Ubvzw Thanks for any advice and suggestions! -- Sent from: http://gis.19327.n8.nabble.com/Mkgmap-Development-f5324443.html