Hi there,
Does anyone know a good data-source of bounding information for
countries, states, counties, cities, etc?
Ideally, this information might be on Wikidata,
https://www.wikidata.org/wiki/Property:P1332 Co-ordinates of
northernmost post
https://www.wikidata.org/wiki/Property:P1333 Co-ordinates of
southernmost post
https://www.wikidata.org/wiki/Property:P1334 Co-ordinates of
easternmost post
https://www.wikidata.org/wiki/Property:P1335 Co-ordinates of
westernmost post
-- but there's very little there yet.
I'm asking because the big 50,000 map georeferencing of the British
Library "Mechanical Curator" maps should be going live in the next two
to three weeks.
A project target would be to get a back-end in place that can upload
maps to Commons *with appropriate categories* within 24 hours of an
image being georeferenced by a volunteer.
A batch of 3000 maps already geo-referenced is available as a test set.
I have had some success using Nominatim on the centre point plus points
40% of the way to each corner, to identify continents, countries, states
and counties that the map appears to be contained within.
But it would be good to know whether it is a map of a whole county, or a
map of several counties, or a map of a large feature within a county.
At the moment, my Nominatim script is a bit cautious, especially for
areas surrounded by sea -- eg Cornwall, Devon, Italy. It's not so good
at recognising that the map is a bit smaller than the encompassing
continent/country/region/county. It would be good to be able to compare
the bounding boxes, to determine how much of the county is in the map,
and vice-versa.
Does anyone know if such data is readily obtainable? Or if there are
good online services from which it could be got on the fly?
Cheers,
James.