https://wiki.openseamap.org/api.php?action=feedcontributions&feedformat=atom&user=WellenvogelOpenSeaMap-dev - Benutzerbeiträge [de]2026-05-09T05:18:32ZBenutzerbeiträgeMediaWiki 1.31.10https://wiki.openseamap.org/index.php?title=OpenSeaMap-dev:Downloadable_Raster_Charts&diff=3350OpenSeaMap-dev:Downloadable Raster Charts2015-01-30T10:11:43Z<p>Wellenvogel: /* formats */</p>
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<div>== Reason for ChartBundler ==<br />
<br />
Lets talk a bit about amounts here and not low stress or high stress.<br />
<br />
Using the charts offline on a mobile device. Lets say the display is about 1024x1024 Pixel, then we will need at least 16 tiles per map. If we start on zoom level 8 with the bounding box and continue to zoom level 16 for the harbours, we need around 2 Mio tiles. This 16 tiles on zoom level 8 is about the northern Adria. If we want the Channel just skipping Lands End up to the belgian coast, this would be 6 by 5 on zoom level 8.<br />
* see [[OpenSeaMap-dev_Diskussion:Downloadable_Raster_Charts|Discussion]]<br />
<br />
== Status Quo ==<br />
<br />
=== prefabricated charts ===<br />
* pros:<br />
** low stress on tile servers<br />
* cons:<br />
** set up needed<br />
** needs to be maintained<br />
** not always up to date<br />
** might not fit users needs <br />
<br />
Links:<br />
* [http://sourceforge.net/projects/opennautical/ OpenNauticalCharts] (outdated)<br />
* [[OpenSeaMap-dev:De:Chart-Bundler|Chart-Bundler]] (work in progress)<br />
<br />
=== on demand ===<br />
* pros:<br />
** up to date<br />
** fits individual needs<br />
* cons:<br />
** high stress on tile servers<br />
** users have to do some research, might be a complex task<br />
<br />
Links:<br />
* [[OpenSeaMap-dev:De:Chart-Designer|Chart-Designer]] (work in progress)<br />
* [http://wiki.openstreetmap.org/wiki/KAP-Dateien_aus_OSeaMap_erstellen OSM-Wiki]<br />
* [http://www.abenteuerland.at/seachart/ smrender-online]<br />
* [http://mobac.sourceforge.net/ MOBAC] (banned by most tile-servers due to unreasonable load)<br />
* [https://code.google.com/p/gmapcatcher/ GMapCatcher]<br />
<br />
== Ideas ==<br />
<br />
=== cache & proxy tile server ===<br />
* [http://tilestache.org/ TileStache] provides<br />
** numerous caches (eg. disk, Memcache, Amazon S3, MBTiles)<br />
** TMS and WMS proxy<br />
** fast and faster [http://www.itopen.it/2012/01/17/serving-your-map-tiles-30-times-faster/ using nginx]<br />
** cache max-age: 30 days?<br />
<br />
=== formats ===<br />
* served by cache & proxy tile server at minimum cost<br />
** tiles in TMS z/x/y directory structure (eg. gps-32, openlayers)<br />
** tiles in TMS z/x/y structure encapsulated in sqlite file ( [https://www.mapbox.com/guides/an-open-platform/#mbtiles mbtiles], eg. tilestache )<br />
** tiles in ??? structure encapsulated in sqlite file (OruxMaps)<br />
** tiles in ??? structure encapsulated in sqlite file (Locus)<br />
** single raster file stiched together via script and imagemagic (eg. .kap/openCPN)<br />
** gemf format - compact format for tiles, can be read by various libraries - e.g. osmdroid, simple to handle [http://www.cgtk.co.uk/gemf gemf format]<br />
<br />
=== bounding boxes/ tile sets ===<br />
* coastal / ocean / open waters<br />
** stick to well known [[OpenSeaMap-dev:Catalogue_of_INT_Charts|INT-charts]]<br />
* inland waterways<br />
** generate corridor (x-tiles wide) along centerline of waterway [http://wiki.openstreetmap.org/wiki/KAP-Dateien_aus_OSeaMap_erstellen#Python-Tool GMapCatcher example]<br />
* lakes<br />
** ...<br />
<br />
=== web frontend ===<br />
* map showing boundingboxes according zoom level [http://www.transas.com/support/marine/chartCorrections/browse transas sample]<br />
* sortable table<br />
* search by name/number/area/purpose<br />
* functions:<br />
** search prefabricated files, check age<br />
** trigger generating script in case file does not exist/ is obsolete<br />
<br />
[[Kategorie:Downloadable Maps]]</div>Wellenvogel