Reference:
http://wiki.openstreetmap.org/wiki/ Slippy_map_tilenames#Zoom_levels
Brief overview:
OSM tiles are 256x256 pixel PNG files.
Filename (URL) format is http://tile.openstreetmap.org/zoom/x/y.png
where
zoom=zoom-level-integer (from 0 to 19),
x=longitude-locator-integer (non-negative column number),
y=latitude-locator-integer (non-negative row number).
See sample code to calculate x and y for a given zoom-level and
a given latitude and longitude, in the 'slippy map' link above.
The following Hawaii Island map is done
with map tiles at OSM zoom level 12.
Approximate latitude,longitude of Hawaii, 'the Big Island':
19.5667 , -155.5000 degrees
Each OSM tile is a 256x256 PNG file.
Each zoom-level-12 tile is one image out of
2^12 x 2^12 = 4096 x 4096 = 16,777,216 images ~ 16 million images
which are used by OpenStreetMap to cover most of the Earth.
These zoom-level-12 tiles go from
x-numbers 272 to 286. (15 columns)
These zoom-level-12 tiles go from
y-numbers 1812 to 1828. (17 rows)
Total: 15 x 17 = 255 tiles
Image width: 15 x 256 = 3,840 pixels
Image height: 17 x 256 = 4,352 pixels
These tiles are fetched from the
OSM server when you (re)load this page.
So these tiles form an image using
the latest versions of the OSM tiles.
This link provides the map in a
*SINGLE* 3840x4352 pixel PNG file
--- created from OSM tiles
as they existed on 19 Feb 2018.
After you access that link,
you can right-click on the image and
use a popup menu option such as
'Save Image As ...' to save the single
image file to your local file system.
This image file was created with a
Tcl-Tk 'tkGooies' script
in the
'MAPtools' group of 'tkGooie' scripts at the
Freedom Environment software web site.
Here is a link to an OSM (openstreetmap.org)
'slippy map'
for
Hawaii ('the Big Island', Wikipedia link) --- initially at zoom-level 12
and centered at latitude and longitude 19.5667 -155.5000,
which is near the center of the island.
Page was created 2018 Feb 19.
Page was changed 2018 Jul 08.
(Added 'slippy map' link.)
Page was changed 2019 Jan 11.
(Added css and javascript to try to handle text-size
for smartphones, esp. in portrait orientation.)
Page was changed 2019 Feb 10.
(HTML changes due to reorg of OSMmaps.)