Hike Bike Map (Hills Underlay) - Offline?
Hardy
Question: Has anybody investigated creating the HBM(Hills Underlay) as an offline-sqlite? Maybe we should think about offering this in our download section in some fashion? (We would need to investigate useful areas, zooms, and manageable file sizes, though).
andre van atten
I use the SRTM hillshade layers in a sqlitedb file as an overlay. Levels 4-11 are stored in one file of only 184 MB, which spans the most of Western Europe. These data is available for the whole world, which is about 30 Gb totally worldwide .
The problem was (of course), that the levels 12 and above were not there and thus not visible anymore when zooming in. However, there was a developer version 0.7x in April 2012 (version 1298), that was able to 'stretch' these images up to level 17. Actually this was a kind of smart resampling and worked rather well! Of course, by resampling the size of the file used to store the hillshade layers could be reduced by a factor 50_100! with nearly no visible loss of quality. There we're sometimes some refresh issues on the edges of the tiles, but easely solved by a manual refresh, and no other big issues. Well, that is one of the reasons I still use this version on a old phone;- )
Would be nice if that was implemented again in version 1.0! But it would also need a distribution process and server to store the sqlitedb files, per country or per latlon degree. A lot of work, indeed.
Andre
Victor Shcherb
Jindřich Makovička
higher zoom level is not available? I remember Yves was working on a
patch that does that, but there were issues with out of memory errors
at that time.
Jindřich Makovička
yvecai
But there was something I wasn't able to fix at that time : https://github.com/osmandapp/Osmand/pull/191, I think the 'exists' method should be separated in case of resampling vs normal sqlite action, and changed accordingly in the ressource manager.
I still have the branch hillshade-resample in my github (https://github.com/yvecai/Osmand/tree/hillshade-resample), I'm pretty sure it can't be merged right away so long after. Maybe you can have a look at it, Jindrich?
I'm building right now (in fact since 2-3 month with a lot of wasted time) a big hillshade sqlite from the same data as the new contours, and I still expect a few weeks of efforts before going there.
Then I'll be able to convert it to Osmand-friendly sqlite, and split it in the same 1x1° tiles as contours so they can be distributed easily with the same plugin.
Victor Shcherb
andre van atten
That's amazing! I am sure it will make Osmand an even more killing app.
Would be nice to add some beautiful pictures on the market when everything is ready and running. But that sure is still a lot of work to be done (..and a lot of work that has been done yet, thanks Yves! ) Are you regenerating all the hillshade tiles to a better resolution ?
Andre
Jindřich Makovička
> I think all the memory issue were solved:
> http://code.google.com/p/osmand/issues/detail?id=858
> But there was something I wasn't able to fix at that time :
> https://github.com/osmandapp/Osmand/pull/191, I think the 'exists' method
> should be separated in case of resampling vs normal sqlite action, and
Do you have some (reasonably small) sqlite tile file this bug can be
reproduced with?
--
Jindřich Makovička
yvecai
Nevertheless you will probably a big sqlite to store the tiles on the server, 'cause rm -rf runs for hours on such a tile set.
Jindřich Makovička
, with the exists() issue hopefully fixed.
Jindřich Makovička
Jindřich Makovička
The hill shading code has been merged last night (thanks Victor!) so
we "only" need to deal with the data :)
For curious folks, I can eventually share the sample sqlite db for a
large part of Western+Central Europe kindly provided by Yves for
testing if he confirms he is ok with that.
Jindřich Makovička
yvecai
Yves
Jindřich Makovička
http://geraldine.fjfi.cvut.cz/~makovicka/SRTM_W-europe_level_4-11.sqlitedb
enjoy :)
On Thu, Dec 6, 2012 at 6:46 PM, yvecai <yve...@gmail.com> wrote:
> Sure, go on if you want, and thanks Andre too to put those tiles in a sqlite.
> Yves
Jindřich Makovička
andre van atten
No thanks, these are the 'old' tiles from November 2011. I use latest dev build 287M, but I see hillshade only on level 12 and below, while I expected them to be resampled up to level 16 or 17, that is on the fly, like the 1298 build . Do I have the right build? Strange thing is that the offline manager tells me that level 2-10 is present in the sqlitedb, while there should be level 4-11??. Hmm, let's sort this out..
Andre
Jindřich Makovička
> No thanks, these are the 'old' tiles from November 2011. I use latest dev
> build 287M, but I see hillshade only on level 12 and below, while I expected
> them to be resampled up to level 16 or 17, that is on the fly, like the 1298
> build . Do I have the right build?
own build. I am not even sure if the scaling is already in the nightly
- there was a build breakage due to errors in translation resources.
> Strange thing is that the offline
> manager tells me that level 2-10 is present in the sqlitedb, while there
> should be level 4-11??. Hmm, let's sort this out..
Jindřich Makovička
Hardy
andre van atten
Works like a charm!
Andre
yvecai
Only 30% of the new hillshade tiles are generated in one week on my server, not sure we get this for Christmas.
Yves
On Friday, December 7, 2012 4:17:30 PM UTC+1, Andre.oid wrote:
Works like a charm!
Andre
Victor Shcherb
Manfred
Shading worked until now.
In #580G this file in /sdcard/osmand/tiles is ignored (not shown as underlay / overlay map any more)
Regards
Manfred