[mkgmap-dev] Garmin Topo Europe map

Sun Jan 3 17:03:33 GMT 2021

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 <7770 at 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-bounces at lists.mkgmap.org.uk> im Auftrag von
> > Pierre Brico <pierre.brico at 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
> > _______________________________________________
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> > mkgmap-dev at lists.mkgmap.org.uk
> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> >
> >
> >
> >
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>
>
>
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