Android OpenStreetMap tracker available offline - android

I'm new at osmdroid and I'm trying to build simple GPS tracking application that must work offline. So first of all I know that osmdroid works with .osm But how to download osm file directly to my android device and more importantly how later I need to use it. I dont understand .osm file is simply just xml with lots of coordinates and other data. So how that .osm file can be transform to a graphical map? I know that is necessary to parse .osm file to get data, but where to download actual graphical map?

osmdroid does not currently present .osm data, mainly due to performance reasons. osmdroid does render raster images that someone can capture into a zip or database and then transfer to device. The problem really is space. It's a big planet and getting raster images can be huge! You'd have to prepare geographic regions into a database then host them somewhere and have your app download them on demand.
osmdroid as a wiki on offline maps here:
https://github.com/osmdroid/osmdroid/wiki/Offline-Map-Tiles
An alternative approach is something like Mapsforge, which can preconvert .osm data into their own binary format, also chunked up by geographic region. Same rules apply, however the file/download sizes are much smaller. Support for osmdroid using Mapsforge is in beta at the moment, however mapsforge can run on it's own and has it's own demo apps and whatnot.
To transform the .osm file into a graphical map, you need something like renderd and a slew of other tools, all on open street maps wiki. Again, you need a boat ton of storage for the planet to convert it into raster images. Then you'd still have to package them somehow and get them on device.
Or you can just use online maps.

Related

How to add style into .mbtiles file

I downloaded a payed .mbtiles file from Open Street Map and managed to create nice maps using openmaptiles-server over Kitematic.
However, I would like to use this .mbtiles file as offline repository of tiles in an Android based application I'm writing.
My plans are to have the mbtiles file stored on an SD card, and let osmdroid MapView read it from there.
However, the file doesn't contain (apparently..) the styling information on its own.
My question is how do I add a styling info such as "OSM Bright" or "Klokantech Basic" to my project so the map on my application looks like a proper map
Many thanks
It's not possible to render bitmap tiles on a device just from information contained in mbtiles data file.
What actually is a mbtiles file?
A mbtiles file is just an SQLite database which contains a very little amount of metadata and rendered bitmap images - tiles Those are the same bitmap files you would be serving online from your openmaptiles-server.
Size of mbtiles file versus size of tiles
MBtiles file size should be almost the same as the overall size of all generated files on your mbtiles server (it's the same number of tiles in each zoom level and the same number of pixels in each tile). If you see a significant difference, it may mean that your mbtiles file doesn't contain the same zoom range (e.g. it doesn't actually contain those most detailed zoom levels) or it contains a smaller area. Some difference may be also caused by a compression algorithm of contained bitmaps and here the actual styling of tiles may play some role (some bitmaps may be easier to compress a resulting PNG may be smaller.
It may be also possible, that the mbtiles file actually contains another image format (jpeg).
If you want to explore what is actually contained in the downloaded mbtiles file, try this tool.
Solution
I don't' think there is a solution when you need to use bitmap tiles. You need to either generate them on a server and download them via network, or you need to prerender them and pack into a mbtile file and download that to a device somehow.
One possible solution would be to use vector maps. It's actually possible to generate vector tiles from Openstreetmap data. Such tiles are than rendered on a device and can actually be styled on the device too.
Unfortunately, Osmdroid library does not support vector tiles at the time of writing (AFAIK). You would have to choose a different map rendering library.

The most compact map file format?

I am trying to understand all this map formats for OpenStreetMap and I really got confused.
The OSM wiki has lots of information, but it looks like it is spread all over different places and i cannot get solid understanding of all the formats.
I am looking for something that can be used in Android for offline use. I know that there are lots of frameworks or even done apps that use different file formats, but as for me they file formats they use are all huge.
As I understand the most lightweight format supported by OSM is PBF-Binary, and it is raster format, right?
I have found that it's possible to convert it to *.map format that is vector, right?
The size then is about 40% less than PBF-Binary, but it has to be rendered and it will not be as fast as raster, right?
So another question is, what is the most compact OSM map format that can be used for android?
I know one app that i use a lot - MapsWithMe and it has small map files and they are very fast, but i don't know if it uses raster or vector, i know only they use OSM maps, but as i understand they have created their own format based on it or smth like that.
I have come across GeoJson and the map files are very small, not more than several megabytes. So now i'm getting confused why it is so, why then it's not used for mobile development, cause i googled 'geojson android' and no information about it.
Are there any comparison tables of these formats?
So if somebody has a link where i can learn about all this things, could you please give it to me?
Thanks
PBF format is a much smaller alternative to XML. It contains the same raw vector data. You can convert from one format into the other without loosing any information. PBF is smaller and faster because it is binary data whereas XML is plaintext. The OSM wiki has a short overview of common OSM file formats.
I don't know where you got the information that GeoJson is small. The size of a map depends on several attributes. Mainly coverage and detail. Usually you don't want to have an offline map covering the whole world on your device because it will be very large. Most of the time you just need a small area, like a country. And often you don't need every information OSM can offer. Roads, cities and important POIs are usually sufficient for routing and searching.
You didn't tell us what you want to do with the map. Just drawing it? Or do you also need a routing and search functionality? What map format would be the most useful for you depends on your use case.
There is already lots of software for Android using OSM, including various open source programs. You can take a look at them if you need inspiration for your software.

Best way to deal with big (shape-)data for map in Android Application

I am building the prototype for an Android app that should result in a versatile map that can deal with a large but static amount of environmental data combined with (user-generated) data that will be hosted on a separate platform.
My current approach is to fetch the large static data via Google Fusion Tables (in original a shape file - .shp, .dbf, .shx that I have exported as a .kml with QGisMaps - the "smaller" .kml I am using is already 66.4MB, the one intended for final use over 140 MB...) I know it is possible to slice down .kml but will this have an effect on loading times?
You can see a current example of the shape data on Google Maps here https://www.google.com/fusiontables/DataSource?snapid=S717313eWaJ
But now I am wondering if I am on the right path at all since this one layer of data is loading very slowly on my machine and I am not aware of the hassle to put this map into an Android app - and more importantly also fetching more data from a separate server and putting it as another (filterable) layer on top of it. This layer will be collected data from users, thus not "static" but regularly updated - integer values displayed in color per geodata.
Several people hinted me to use Open Street Maps but some advised that Android is very eloquent with Google Maps - in the middle of development I thought maybe someone can tell me whether I chose the right direction to go for or are most likely facing less problems with an alternative solution.
I would be really glad if someone could advise me on the issue with combining map data from two different sources layerd onto one map in Android whereas one bunch of data is huge but static and the other user-generated values.
Thanks so much for your time and looking over this
best
Birgit
EDIT #1: I am now switching to Open Street Maps, hoping to be able to set up a GeoServer myself hosting the data and querying the WMS with the App. It seems like the size of the data still has to be compressed in some way, I will keep you updated.
I'll not be able to address all of your concernes, but I can share some of my experience with maps and ovelays.
The most important concept you must be aware is the memory heap. Each android application has a maximum memory amount that can be used to allocate data objects, called memory heap. This limit is different from device to device and can go from 16MB in small older devices to 64MB in new tablets.
Having said that, you will never be able to load all your data at one shot if the data structure required to hold it exceeds the maximum heap available for the application.
Also, usaging large amounts of memory makes your application better candidate to be terminated by users or by the SO when additional memory is required by critical activities (like a phone call).
Now, going to the maps part...
I've used Google maps as well as mapsforge api for OpenStreet maps. Google maps requires internet connection, while mapsforge enables you to use a local map file or online connection. OpenStree maps don't provide the sattelite view.
Regarding performance, online connection tends to be faster, as they download already rendered map images, while offline map requires the images to be rendered as needed. Mapforges can use a local cache to improve this a little.
Displaying Overlays:
I've used both API's to display paths with arround 10.000 points over a map, together with additional overlays (compass, scale bar, pop-ups, etc.) and the code runs smoothly in a mid-rande device. However, my code have some optimizations to reduce recreation of paths (when user zoom or move map) by transforming the already existing path.
good luck.
So this is how I eventually converted a .shp file into a format that could be displayed by OSMdroid's XYTilesource.
I exported the layers separately as .kml projected WGS84 and imported them as layers to TileMill. After having defied the colors for each layer in CSS, I exported my map as a set of MBTiles. I uploaded them to Mapbox.com. From there I can fetch the tiles which are in the format a.tiles.mapbox.com/v3/myUsername.myTiles/{z}/{x}/{y}.png in my OSMdroid Mapview.
final myTileSource tileSource = new XYTileSource("myTiles", null, 10, 16, 256, ".png", "http://a.tiles.mapbox.com/v3/myUserName.myTiles/");

osmdroid sqlite tile source

I want to add a SQLite tile provider to OSMDroid just like RMaps. I went through OSMDroid source code and its tile providers and I found that they are designed to get tiles from File, Archive file and internet.
I am using osmdroid-android 3.0.5.
I don't belive this is possible with the current Osmdroid library. If you want to do it you will have to create your own TileProvider to fit into the framework which should be possible.
I expect that using an archive file for the actual map tiles and a seperate database for your meta data is by far the simplest solution. Putting large amounts of data like the tiles into the database is not recomended.
Have a look at this page. I think this is what you are looking for :o)
I recently implemented a sqlite storage for the tiles of the osmdroid lib, and the only thing missing is the ability to create it with mobac. So I wrote this patch to provide the new output option. Please have a look and commit it if you like it. Let me know if you think I should change something.

Osmdroid: How I can create and load a map from my own bitmaps(tiles)?

I am starting to use Osmdroid and I would like to use this technology for showing a map about an F1 circuit. I have a big picture and I can cut it up to divide it into smaller tiles.
Can I modify the osmdroid library for the upload of these pictures?
I would like to save these bitmaps (tiles) in my assets folder.
I am pretty lost on how to do this.
I am using this way because android, normally, gives a memory error when I try show this complete full-size picture. If I only show some tiles of the image (depends of the zoom) maybe my app would work better?
Thanks in advance!
Osmdroid uses a system in which world map is divided into tiles. Tiles usually have the same pixel size which means that the bigger zoom level you use the more tiles are needed to "cover the world". Each tile has its coordinates (x,y) and a zoom level in which it is designed to be used.
It is possible to use various custom tile sources in osmdroid. Take a look at this class in osmdroid - it creates instances of some tile sources. You can create your own tile sources using the same mechanism. However, all this uses these x,y coordinates of the world I described above. Osmdroid will ask your tile source for example for tile 10,10 in zoom level 10. If you are able to create tiles of your map to work with this coordinates system then it will work. However, it may be hard to do this for custom maps such as F1 circuits.
I am also interested in this and probably will try to use tiling mechanism of osmdroid to display some big images in the near future. If you succeed in this please let me know:).
I think there's two questions here:
How to create osmdroid format map tiles from a bitmap file.
How to load them into osmdroid
For question 1 you can use a tool to create your tiles.
http://www.maptiler.org/
Can be used to create tiles from a bitmap giving in your bitmap and its boundaries coordinates.
http://mobac.sourceforge.net/
Creates Atlas from online maps, it can create osmdroid zip atlas. Not sure if you could use it to create your osmdroid zip format.
If Mobile Atlas creator doesn't help perhaps you can create the zip manually if your source bitmap is not too big.
For question 2:
I extended an osmdroid class to deploy maps in an apk using the asset folder. See here:
https://stackoverflow.com/a/14832770/891479

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