Base types for retrieving and saving tiles in resources. A
TiledResource if a resource capable to describe its tiling schemes as
TileMatrixSet is a collection of
TileMatrix instances in the same CRS but at different scale levels.
TileMatrix is a collection of
Tile instances with the same size and properties placed on a regular grid with no overlapping.
The "tile" word is used because of its wide usage with two-dimensional data, but actually this package has no restriction
on the number of dimensions and can work with multi-dimensional "tiles" as well.
- OGC Two Dimensional Tile Matrix Set — the core standard used in this package.
- OGC Web Map Tile Service (WMTS) — a common use of above standard.
- OGC Geopackage: Extension for Tiled Gridded Coverage Data — another common use.
- OGC Geopackage: Extension for vector tiles — experimental work for tiled geometries.
Relationship with OGC specificationsThe
TileMatrixSet class names are reused as defined by OGC.
The "2D" suffix in class names is omitted because this package is fully multi-dimensional.
The concept of "tiling scheme" is encapsulated in a
Departures with OGC specificationsThe OGC
TileMatrixLimits class is replaced by
The OGC restriction against negative numbers is removed (Apache SIS accepts negative tile indices).
The tile span and tile matrix min/max coefficients are replaced by a more generic
"grid to CRS"
MathTransform, usually affine but not necessarily.
Users may need to enforce above OGC restrictions themselves if compatibility with OGC specification is desired).
Relationship with Java2D rendered imageOGC tiles can be mapped to Java2D tiles with the following restrictions:
- Java2D tile indices and pixel indices are 32 bits integer instead of 64 bits. See grid coverage render (in particular the relative pixel coordinates) for the workaround applied in Apache SIS.
- Java2D does not support coalescence coefficient (used in OGC tiles for compensating distortions near poles).
Tiles in Java2D are expanded as needed as if the
TileMatrixhad no coalescence.
ClassDescriptionA small hyper-rectangular representation of data which is part of a tiling scheme.A resource which content can be accessed by smaller chunks called tiles.A collection of tiles with the same size and properties placed on a regular grid with no overlapping.A collection of
TileMatrixin the same CRS but at different scale levels.Information about the availability of a tile.A
TiledResourcethat can write and delete tile matrix sets.A
TileMatrixthat can write and delete tiles.A
TileMatrixSetthat can write and delete tile matrices.