#Maptiler change zoom level software#
#Maptiler change zoom level series#

The numbering of a tile at zoom level k is described by a pair of integers (x,y), where x is the column number of the tile, starting from the longitude of 180 degrees and heading East, and y is the row number of the tile, starting from the latitude of +85.0511 degrees and heading South (Figure 1).įigure 1. The number of tiles at zoom level k is equal to 4^k, e.g., at zoom levels 3 and 17, there are 64 and 17,179,869,184 tiles, while the ground resolution is 20km and 1.19m per pixel, respectively. As the size of each new tile is still 256×256 pixels, the pixel size at level k+1 is four times smaller than the pixel size at level k. Each tile at any zoom level k is replaced by 4 equal-sized tiles at zoom level k+1. The projection adopted for all tiles is Web Mercator with WGS’84 datum. This layout depicts the earth on the Web Mercator projection (latitude values range roughly from -85.0511 to +85.0511 degrees), and excludes polar areas. The world is rendered in a single tile at the outer most zoom level and numbered as 0. All map tiles are square-shaped and equal sized, i.e., 256×256 pixels. Google Maps conventions for these values are as follows. The standardization of the values for the above properties may save time in rendering the fetched tiles in the client. Combining tiles from various servers, including mapping providers, might involve some simple or complex transformations. These properties include the shape and size of tiles, numbering of zoom levels, subdivision scheme of a tile to result the tiles in the next zoom level, numbering of individual tiles, and map projection of tiles.

#Maptiler change zoom level series#

The creation of map tiles is according to the values of a series of properties.

In the former, a group of layers are combined into a single image per tile, while in the later these layers appear in the client as a collection of layers with enabled feature selection and controllable visibility. They also support single fused and multi-layer tiles.

#Maptiler change zoom level software#

GIS software vendors, like Esri and Oracle, provide functionality for map tiling and caching of both vector layers and raster images. Others, like Bing and OpenStreetMap, followed the same practice.

Google was one of the first major mapping providers to adopt the tiled web maps. In this way, the time required for the client to display complex and high quality base maps is mainly limited by the bandwidth of its connection with the map server. With the increasing popularity of web mapping applications and the rapid growth of map data availability, the pre-computation and caching of map image tiles has become a common practice in map servers as they use far fewer server resources than maps rendered on demand. Large paper maps have always been divided into a series of map sheets at various scales. The tiling of large maps is an old practice.