Garmin city navigator maps use 23. Else a Europe map within 4GB is out of question. However they use NT format too, which is about 1/3 smaller additionally.
Same I guess for their Topo Europe maps. On Mon, 4 Jan 2021, 01:03 Pierre Brico <pierre.br...@gmail.com> wrote: > Hi Karl, > > Thanks for your analysis, very instructive. I've tried several of your > steps and arrived at the conclusion that it's not a good idea to set the > resolution to 23. Here are the 2 main reasons: > 1. as you mentioned the map becomes less accurate, some roundabouts are > converted into triangles, some line segments are misaligned ... > 2. from the cgpsmapper guide: "IMG file should be created with Level 0 > equal to 24 – otherwise distance calculation might be wrong" > > Do you know if the Garmin TopoActive map uses resolution 23 or 24 ? > > Pierre > > On Sun, Jan 3, 2021 at 8:21 AM 7770 <7...@foskan.eu> wrote: > >> Hi. >> I made a few tests to lower the size of the maps. >> >> Comparison is made to my standard map which is based on the styles >> example in >> mkgmap but extended a bit for my purposes. This has 100 % size. >> There are 4 levels, 24 is the most detailed resolution. >> >> Setting the resolution to 23 and changing relevant polygons, lines, >> points to >> show at 23 instead of 24. 4 levels (option file). >> Size 78 %. >> >> Setting the resolution to 23 and changing relevant polygons, lines, >> points to >> show at 23 instead of 24. 3 levels (option file). levels = 0:23, 1:20, >> 2:18 >> Size 64 %. >> >> >> Using my minimal style (discussed earlier in this thread). >> Compared to normal map, it is about 75 % in size. >> >> Using minimal style and >> Setting the resolution to 23 and changing relevant polygons, lines, >> points to >> show at 23 instead of 24. 4 levels (option file). >> Size 63 %. >> >> Using minimal style and >> Setting the resolution to 23 and changing relevant polygons, lines, >> points to >> show at 23 instead of 24. 3 levels (option file). levels = 0:23, 1:20, >> 2:18 >> Size 51 %. >> >> >> I noted that when resolution is set to 23 polygons smaller than the >> mentioned >> raster at ~4.8 m disappear. They also do get distorted. Buildings are >> such >> polygons that are effected a lot, and it is (in my opinion) a good idea >> to >> disable buildings and similar polygons entirely when lowering the >> resolution. >> Coast lines and alike become less detailed of course. >> Some line segments have become a bit misaligned (i noted bus stop >> platforms >> and similar short lines can have this issue). >> >> >> I yet have to check how well these maps work on a unit but it seems >> possible >> to lower the size quite a lot if it is desired. >> >> >> Regards >> Karl >> >> >> >> >> On onsdag 30 december 2020 kl. 13:27:06 CET Vuki wrote: >> > Hi, >> > >> > am also working on a "lite" style and there may be some nice idea in >> yours >> > to use :) will check that out, thanks! >> > >> > >> > Köszi: >> > Vuki >> > On 2020.12.30. 12:08, 7770 wrote: >> > >> > Hi. >> > I am ok with sharing the style, but i was not able to do it until today >> > (planned today or tomorrow). >> > 5 files attached, 4 related to style, 1 to TYP (foskan.txt). >> > Only those 4 style files have changes, compared to the standard. >> > >> > The complete set of files is ./mkgmap-rNNNN/examples/styles/default/ >> > >> > >> > There is nothing fancy nor complex, nor have i played around with the >> levels >> > yet. >> > >> > For reference i also added my TYP-file, which may help in case you find >> some >> > type codes which are non standard (there might be a few). The type file >> is >> > shared and does contain a few things that are not used by the minimal >> style >> > (don't get confused). >> > >> > >> > Summery of the style, which is based on the default mkgmap example. >> > All changes comments are marked with ## to be able to tell them apart >> from >> > regular comments given after #. >> > >> > polygons and points do have a lot of disabled information. >> > Buildings, shops, and most of the parking types are disables. >> > >> > lines doesn't have as many changes and probably a few more small >> waterways >> > (streams, rapids, waterfalls) can be disabled to remove yet a bit of >> data. >> > >> > note for polygons. >> > Waters and forests are still visible, since it adds information to the >> map, >> > but if natural objects are not important for you, there is more space to >> > save. >> > >> > i have made one change in lines file to display the road name on >> tertiary >> > roads instead of the reference. this does make sense in nordic >> countries, >> > where tertiary roads are usually only referred to with the name. >> > >> > Ski lifts (arealways in general) are set in similar way as railroads. >> > >> > One last thing to mention is that i have updated the inc/address file. >> > Close to the end there is a section in which the mkgmap:phone is >> updated to >> > show information about which fuels are sold at fuel stations. This is >> not >> > fully complete for all fuel types but the ones i somehow considered >> > important. Depending on where one is, a few more fuel types can easily >> be >> > added. >> > >> > A note. >> > The mkgmap:phone seems to be 50 characters maximum, longer data will be >> > truncated and not shown on the device it seems. >> > >> > >> > Regards and happy new year! >> > Karl >> > >> > On onsdag 30 december 2020 kl. 10:16:51 CET Vuki wrote: >> > >> > Hi Karl, >> > >> > don't you want to share your minimal style? :) >> > >> > >> > Köszi: >> > Vuki >> > On 2020.12.27. 20:59, 7770 wrote: >> > >> > Hi. >> > A few observations about the TopoActive europe map. (i have it on a >> GPSMAP >> > 66st). >> > >> > The map is rendered slower than most custom made maps. >> > Updates occur 2 times per year, but even at those times many changes to >> OSM >> > are not present. Perhaps they only update some parts yearly. >> > Points lack all kind of additional information which other mappers add >> > (opening hours, region, phone numbers, etc.). >> > One nice thing is colour marked national parks and reserves. >> > Being an outdoor map, it lacks some information about shelters in the >> > wilderness. >> > Routing is possible only for outdoor activities (cycle, walk, hike, >> direct), >> > automotive routing (car, motorcycle) is disabled. >> > >> > I have tried creating a minimal style. This lowers the data to about 75 >> % or >> > my normal set up. But i did not change the level, which i will try :-) >> > Currently I am no way near the compression which TopoActive achieves. >> Using >> > input data which is about 6,7 GB in pbf format, creates a gmapsupp just >> > below 4 GB for normal and around 3 GB for minimal style. These numbers >> > feels similar to getting France into 1.9 GB from 3.7 GB pbf (geofabrik). >> > >> > >> > The minimal set up is not very fancy at all, it disables things not >> wanted. >> > Buildings, shops, most of parkings, and a bit more. >> > >> > Today i cannot send off any style, but in case that would be of >> interest let >> > me know and i can share it in a few days (guessing Wednesday or >> Thursday). >> > >> > >> > Regards >> > Karl >> > >> > On söndag 27 december 2020 kl. 20:08:10 CET Gerd Petermann wrote: >> > >> > Hi Pierre, >> > >> > my first guess would be that the level 0 is at resolution 23 instead of >> 24. >> > >> > Gerd >> > >> > ________________________________________ >> > Von: mkgmap-dev <mkgmap-dev-boun...@lists.mkgmap.org.uk> im Auftrag von >> > Pierre Brico <pierre.br...@gmail.com> Gesendet: Sonntag, 27. Dezember >> 2020 >> > 19:37 >> > An: Development list for mkgmap >> > Betreff: [mkgmap-dev] Garmin Topo Europe map >> > >> > >> > Hello guys, >> > >> > I've just discovered the Garmin TopoActive Europe map based on >> OpenStreetMap >> > data. This map is sold at a price of 50€ or is pre-installed on some new >> > devices. I've just seen it on the device of one of my friends and it >> looks >> > very good. I'm surprised to see that for West Europe, it takes only >> 2.8GB >> > and is quite complete (index for search, routable, ...). >> > >> > For now, I generate my own maps based on your excellent tool but the >> result >> > is much bigger (1.9GB only for France with probably more details). So, >> my >> > question is: does anybody have a similar configuration (style files and >> > command line) to obtain a result like the Garmin TopoActive Europe ? >> > >> > Thanks, >> > Pierre >> > _______________________________________________ >> > mkgmap-dev mailing list >> > mkgmap-dev@lists.mkgmap.org.uk >> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev >> > >> > >> > >> > >> > _______________________________________________ >> > mkgmap-dev mailing list >> > mkgmap-dev@lists.mkgmap.org.uk >> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev >> >> >> >> _______________________________________________ >> mkgmap-dev mailing list >> mkgmap-dev@lists.mkgmap.org.uk >> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev > > _______________________________________________ > mkgmap-dev mailing list > mkgmap-dev@lists.mkgmap.org.uk > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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