Create Offline Map - Zoom level

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Relaxer

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Sep 30, 2010, 8:14:45 PM9/30/10
to Osmand
I don't really understand what zoom levels needed to create/save
custom offline map.

I did create a sql file from part of a map with Google Maps as source
at zoom level 17.
But, for all zoom levels less than 17, just get checkerboard squares.

What is the English meaning of this in the wiki:
"You can preload data for zoom 15 & application will automatically
expand tiles up to 17. There is no sense to load 15 zoom and do not
load 14 zoom because size 15th zoom > 1-14th zoom. I"

It does not make any sense to me 'there is no sense to load 15 zoom
and do not load 14 zoom....'

Is this supposed to mean that if you are going to preload data for
zoom 15, you need ALL zoom levels up to 15?

Victor Shcherb

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Oct 1, 2010, 9:34:43 AM10/1/10
to Osmand
Sorry for english on wiki pages. It introduced some misunderstanding.

You are right you should preload ALL zoom levels up to 17 (in your
case).
Osmand application can only upscale image tiles from level to level+1
and level + 2, but it can't downscale.
The main idea : if you need to download area with 17th zoom you should
also download all areas from 1-16th zoom, but you shouldn't worry that
unusefull information. Because the image data 1-16th zoom keeps twice
less disk space than information of 17th zoom.

reggiehg

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Nov 29, 2010, 5:25:41 PM11/29/10
to Osmand
Hi, I'm trying to understand the downloading process. I've set the
screen to metro manila, philippines at zoom 11 & set max zoom to 19.
(What does auto zoom map mean?) Will osmand now download all tiles for
the entire area up to zoom 19 automatically? I tried leaving my gprs
connection on for a few hours, & then turned it off to check the
results. But when I zoomed to higher levels, some maps haven't been
downloaded. I think my main problem is I can't find any indicator of
the downloading progress. Is there a way to know if all areas on the
screen have been downloaded to the desired zoom level? It's not
practical to check all the areas!

Also, what are the pros & cons of preloading? Isn't preloading the
same as automatic downloading?

Finally, I downloaded the osmandmapcreator & extracted it, but don't
know how to proceed. Do I need to download java 1.6? I can't find that
on market. Tia.

On Oct 1, 9:34 pm, Victor Shcherb <vics...@gmail.com> wrote:
> Sorry for english on wiki pages. It introduced some misunderstanding.
>
> You are right you should preload ALL zoom levels up to 17 (in your
> case).
> Osmand application can only upscale image tiles from level to level+1
> and level + 2, but it can't downscale.
> The main idea : if you need todownloadarea with 17th zoom you should
> alsodownloadall areas from 1-16th zoom, but you shouldn't worry that
> unusefull information. Because the image data 1-16th zoom keeps twice
> less disk space than information of 17th zoom.
>

Goedson Teixeira Paixao

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Nov 30, 2010, 8:19:47 AM11/30/10
to osm...@googlegroups.com
2010/11/29 reggiehg <regg...@gmail.com>:

> Hi, I'm trying to understand the downloading process. I've set the
> screen to metro manila, philippines at zoom 11 & set max zoom to 19.
> (What does auto zoom map mean?) Will osmand now download all tiles for
> the entire area up to zoom 19 automatically?

Autozoom means you will have the application automatically change the
zoom level based on your current speed so you can have a good view of
where you are heading to. So, you have lower zoom levels for higher
speeds.

> Also, what are the pros & cons of preloading? Isn't preloading the
> same as automatic downloading?

By preloading the tiles, you don't need a data connection as long as
you're in the area you've already preloaded.

> Finally, I downloaded the osmandmapcreator & extracted it, but don't
> know how to proceed. Do I need to download java 1.6? I can't find that
> on market. Tia.

OsmAndMapCreator is an application to be used in your desktop in order
to create preloaded sets of tiles and indexes of POIs, addresses, etc.
Using it, you can, for example, mark a given area and command the
download of the tiles for that area in some chosen zoom levels. After
that, you can copy the tiles to your phone and use them in osmand.

--
Goedson Teixeira Paixao

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