Hi Ticker, I tried this patch with r4734 and I see no improvements. Maps are larger, more white rectangles in sea. Maybe my recent changes don't work well with yours? Do you have an example where it improves something with r4734? Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap@jagit.co.uk> Gesendet: Freitag, 21. Mai 2021 18:10 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] Problems with sea in overview map Hi Gerd I'd been doing some investigation of filters ordering (based on trunk). I'd also done the pre-filtering of lines & shapes by minRes. My conclusions are: Shapes: It is better to run SizeFilter after RemoveObsoleteFilter. It is more efficient to run DP filter after both of these. Lines: LineSplitterFilter should be run after everything that can remove points. It is more efficient to run DP after RemoveObsoleteFilter. I've adapted my changes into a patch for the low-res-opt branch, along with removal of some resolution tests that are now redundant. For the contourFilters, I've left DP as the first filter but moved LineSplitter as for the normalFilters Ticker