Definitions
yup: in the context of web-map-tiles yup
means “y-up”; z/x/y tile servers serve tiles with y-down
coordinates, while mbtiles
and geopackage
files store tiles as y-up
. Converting between y
and yup
is done by yup = 2^z - y - 1
where z
is the zoom level. Converting in a sqlite
database can be done like this:
SELECT zoom_level AS z,
tile_column AS x,
(2^zoom_level - tile_row - 1) AS y,
tile_row AS yup,
FROM tiles;
zoom-level: Map zoom level 0 - 30
tile: A tile is a square image of a specific zoom level, typically 256x256 pixels. Tiles are used to display map data at different zoom levels.
zbox: Utiles name for a tile-bounding-box at a zoom level - defines zoom, min-x, min-y, max-x, max-y for querying tiles
tilejson: A JSON object that describes a tile set, including its name, description, and the URL template for accessing tiles. TileJSON is used to provide metadata about a tile set.
textiles: utiles name for an ndjson/jsonl file containing tiles as arrays or objects (e.g. [x, y, z]
or {x: x, y: y, z: z}
)