User:Kannix/tile-download-scheme

given:

• .mbtiles database, containing only tiles that cover navigable waterways (e.g. cemt.mbtiles)
• grid of download areas (boundingboxes like tiles at zoom-level 7 look good, see https://kap.grade.de/inland-chart-ol2.html )

steps:

• extract all z/x/y from .mbtiles for selected boundingbox (zoom-level 15 seems to be a good choice)
  • see inland.ods for SQL selects
  • eg. boundingbox=tile z=7 x=65 y=45
  • save result as 7_65_45.csv
• calculate corridor of tile names around the extracted tile names
  • see csv-15.py_
  • result is saved as 15_optimized.csv
• calculate list of tile names at zoom-level 14-7
  • see csv-14-7.py_
  • result is saved as [zoomlevel]_optimized.csv
• download tiles