OGC API - Tiles
OGC API - Tiles specifies a standard for Web APIs that provide tiles of geospatial information.
Different forms of geospatial information are supported, such as tiles of vector features ("vector tiles"), coverages, maps (or imagery) and potentially eventually additional types of tiles of geospatial information.
Vector data represents geospatial objects such as points, lines, and polygons. Tiles of vector feature data (i.e. Vector Tiles) represent partitions of vector data covering a large area (e.g. lines representing rivers in a country).
In this context, a map is essentially an image representing at least one type of geospatial information. Tiles of maps (i.e. Map Tiles) represent subsets of maps covering a large area (e.g. a satellite image).
Core
The Core conformance class of OGC API - Tiles simply requires that tiles can be retrieved according to a tile matrix set, using some template URL made up of:
- a tile matrix,
- a tile row, and
- a tile column.
That URL template and information about the tileset can either be provided through the Tileset conformance class, or by some outside mechanism.
Tileset & Tilesets List
The Tilesets List and Tileset conformance classes defines transportable end-points:GET .../tilesRetrieves the list of tilesets available (tilesetsarray property whose elements containlinksto the tileset withselfrelation type)GET .../tiles/{tileMatrixSetId}Retrieves the metadata for a specific tileset (tiled according to a particular tile matrix set).GET .../tiles/{tileMatrixSetId}/{tileMatrix}/{tileRow}/{tileCol}Retrieves a tile from a specific tileset (tiled according to a particular tile matrix set) in the requested tile matrix set, on the requested tile matrix (e.g. zoom level) with the requested row and column.
Dataset & GeoData Tilesets
The Dataset Tilesets conformance class defines how a list of tilesets can be associated to an OGC API dataset / landing page, while the GeoData Tilesets conformance class defines how a list of tilesets can be associated to an OGC API collection.
By combining Tiles building blocks with other OGC API standards, different types of tilesets can be provided from a single API:
Vector tiles:
(link relation: http://www.opengis.net/def/rel/ogc/1.0/tilesets-vector)
{datasetAPI}/tilesDataset tilesets (multi-layer vector tiles){datasetAPI}/collections/{collectionId}/tilesCollection tilesets (vector tiles)
Map tiles (OGC API - Maps):
(link relation: http://www.opengis.net/def/rel/ogc/1.0/tilesets-map)
{datasetAPI}/map/tilesDataset map tilesets{datasetAPI}/collections/{collectionId}/map/tilesCollection map tilesets
Coverage tiles (OGC API - Coverages):
(link relation: http://www.opengis.net/def/rel/ogc/1.0/tilesets-coverage)
{datasetAPI}/collections/{collectionId}/coverage/tilesCollection coverage tilesets
Styled vector tiles, e.g. filtered by scale (OGC API - Styles):
(link relation: http://www.opengis.net/def/rel/ogc/1.0/tilesets-vector)
{datasetAPI}/styles/{styleId}/tilesStyled dataset tilesets (multi-layer vector tiles){datasetAPI}/collections/{collectionId}/styles/{styleId}/tilesStyled collection tilesets (vector tiles)
Styled map tiles (OGC API - Maps and OGC API - Styles):
(link relation: http://www.opengis.net/def/rel/ogc/1.0/tilesets-map)
{datasetAPI}/styles/{styleId}/map/tilesStyled dataset map tilesets{datasetAPI}/collections/{collectionId}/styles/{styleId}/map/tilesStyled Collection map tilesets