OpenSeaMap-dev:Downloadable Raster Charts: Unterschied zwischen den Versionen

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(Reason)
(prefabricated charts: kap.grade.de added)
 
(4 dazwischenliegende Versionen von 2 Benutzern werden nicht angezeigt)
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== Reason for ChartBundler ==
+
== Discussion ==
 
 
Lets talk a bit about amounts here and not low stress or high stress.
 
 
 
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.
 
 
* see [[OpenSeaMap-dev_Diskussion:Downloadable_Raster_Charts|Discussion]]
 
* see [[OpenSeaMap-dev_Diskussion:Downloadable_Raster_Charts|Discussion]]
  
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* [http://sourceforge.net/projects/opennautical/ OpenNauticalCharts] (outdated)
 
* [http://sourceforge.net/projects/opennautical/ OpenNauticalCharts] (outdated)
 
* [[OpenSeaMap-dev:De:Chart-Bundler|Chart-Bundler]] (work in progress)
 
* [[OpenSeaMap-dev:De:Chart-Bundler|Chart-Bundler]] (work in progress)
 +
* [http://kap.grade.de/ kap.grade.de] (showcase)
  
 
=== on demand ===
 
=== on demand ===
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=== formats ===
 
=== formats ===
 
* served by cache & proxy tile server at minimum cost
 
* served by cache & proxy tile server at minimum cost
** tiles in TMS z/x/y directory structure
+
** tiles in TMS z/x/y directory structure (eg. gps-32, openlayers)
** tiles in TMS z/x/y structure encapsulated in sqlite file ( [https://www.mapbox.com/guides/an-open-platform/#mbtiles mbtiles] )
+
** tiles in TMS z/x/y structure encapsulated in sqlite file ( [https://www.mapbox.com/guides/an-open-platform/#mbtiles mbtiles], eg. tilestache, OruxMaps, Locus)
** tiles in ??? structure encapsulated in sqlite file (OruxMaps)
+
** single raster file stiched together via script and imagemagic (eg. .kap/openCPN)
** tiles in ??? structure encapsulated in sqlite file (Locus)
+
** 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]
** single raster file stiched together via script and imagemagic
 
  
 
=== bounding boxes/ tile sets ===
 
=== bounding boxes/ tile sets ===

Aktuelle Version vom 27. Februar 2015, 16:04 Uhr

Discussion

Status Quo

prefabricated charts

  • pros:
    • low stress on tile servers
  • cons:
    • set up needed
    • needs to be maintained
    • not always up to date
    • might not fit users needs

Links:

on demand

  • pros:
    • up to date
    • fits individual needs
  • cons:
    • high stress on tile servers
    • users have to do some research, might be a complex task

Links:

Ideas

cache & proxy tile server

  • TileStache provides
    • numerous caches (eg. disk, Memcache, Amazon S3, MBTiles)
    • TMS and WMS proxy
    • fast and faster using nginx
    • cache max-age: 30 days?

formats

  • served by cache & proxy tile server at minimum cost
    • tiles in TMS z/x/y directory structure (eg. gps-32, openlayers)
    • tiles in TMS z/x/y structure encapsulated in sqlite file ( mbtiles, eg. tilestache, OruxMaps, Locus)
    • single raster file stiched together via script and imagemagic (eg. .kap/openCPN)
    • gemf format - compact format for tiles, can be read by various libraries - e.g. osmdroid, simple to handle gemf format

bounding boxes/ tile sets

  • coastal / ocean / open waters
  • inland waterways
  • lakes
    • ...

web frontend

  • map showing boundingboxes according zoom level transas sample
  • sortable table
  • search by name/number/area/purpose
  • functions:
    • search prefabricated files, check age
    • trigger generating script in case file does not exist/ is obsolete