S2Tiles is a derivative of the MBTiles spec
S2Tiles is a specification for storing arbitrary tiled map data in SQLite databases for immediate usage and for efficient transfer. S2Tiles files, known as tilesets, must implement the specification below to ensure compatibility with devices.
S2Tiles is a compact, restrictive specification. It supports only tiled data, including vector or image tiles and interactivity grid tiles. Only the S2 projection is supported for presentation (tile display), and only U-V coordinates are supported for metadata such as bounds and centers.
It is a minimum specification, only specifying the ways in which data must be retrievable. Thus S2Tiles files can internally compress and optimize data, and construct views that adhere to the S2Tiles specification.
Unlike Spatialite, GeoJSON, and Rasterlite, S2Tiles is not raw data storage. It is storage for tiled data, like rendered map tiles.
One S2Tiles file represents a single tileset, optionally including grids of interactivity data. Multiple tilesets (layers, or maps in other terms) can be represented by multiple S2Tiles files.
The text of this specification is licensed under a Creative Commons Attribution 3.0 United States License. However, the use of this spec in products and code is entirely free: there are no royalties, restrictions, or requirements.
The original MBTiles authors can be seen here
- Craig O'Connor (CraigglesO)