Hi Ticker, I think the problem is that PredictFilterPoints ignores the fact that the DouglasPeuckerFilter typically reduces the number of nodes. The result is that many shapes are split although they would not have too many points after DouglasPeuckerFilter. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Gerd Petermann <GPetermann_muenchen@hotmail.com> Gesendet: Freitag, 3. Februar 2017 19:28:13 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] r3784 produces large img files than r3773 Hi Ticker, my impression is that the new algos are more likely to place nearby objects into different sub divs, that would be bad for ShapeMergeFilter, esp. without --order-by-decreasing-area. I'll try to find out more tomorrow if you have no simple fix for that. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap@jagit.co.uk> Gesendet: Freitag, 3. Februar 2017 18:56:06 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] r3784 produces large img files than r3773 Hi Gerd Most of the changes that will make a difference to size are related to MapArea/SubDivision contents and splitting hence ShapeMergeFilter activity. As far as changes in size between the versions: 3782-3784 should be similar and a little bit worse than 3781 because of a fix to stop a large subdivision being extended on both sides 3781 should be quite a lot better than 3780 because it stops irrelevant items being added to the MapArea data usage count, triggering more splitting than necessary 3779 should be better than 3778 because it should stop a lot of splitting at lower resolution 3778-3774 should be broadly similar Relating to a given version with and without OrderByDecreasingArea: I've always found images a bit bigger - sometimes up to 4% for areas with large numbers of adjacent buildings that shapeMergeFilter joins. I haven't done anything intentional that would change this in any of the recent revisions. I'm not sure if this answers your question Ticker On Fri, 2017-02-03 at 16:32 +0000, Gerd Petermann wrote:
Hi Ticker,
I compared the sizes for a map of spain with and without option - -order-by-decreasing-area, I always see larger files with r3784. With r3777 and r3778 the files are typically a bit smaller than with r3773. Is there a good reason for that ?
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