Layertile

Layertile is a concept used in geographic information systems and web mapping to denote a single tile that represents data for one map layer at a given zoom level. It extends the traditional tile idea by attaching a specific layer identifier to the tile, allowing multiple layers to be tiled and retrieved independently.

In a layertile, the payload can be raster data or vector features corresponding to the geographic extent of the tile. The tile is typically addressed by a standard tiling scheme (for example XYZ or TMS) using coordinates (x, y, z) and is accompanied by metadata such as the layer name, styling information, and data provenance.

Applications include multi-layer maps where base imagery, labels, roads, and thematic data are rendered by combining layertiles from different layers on the client side. This approach supports selective loading, offline caching of individual layers, and efficient updates when a single layer changes.

Performance considerations include potential data duplication across layers, increased number of HTTP requests, and cache management complexity. Proper tiling strategy, compression, and server-side aggregation can mitigate these issues.

Layertile is not a universally standardized term; implementations vary and some systems expose per-layer tiles under different naming conventions. It is closely related to concepts such as vector tiles, raster tiles, and multi-layer rendering pipelines.

See also: tile, vector tile, raster tile, map tiling, layers.