![mapproxy tms resolutions zoom levels mapproxy tms resolutions zoom levels](https://i.stack.imgur.com/3V6oc.png)
Needless to say, no consumer grade computer can handle such an image, not to mention the time and bandwidth required to download it from the internet. At the 20th zoom level, the size has grown to 134 million by 134 million pixels, an image that even assuming some pretty good compression would be about 25 terrabytes in size. Image sizeĪ problem with this approach is that while increasing the scale, the image size quickly grows to sizes that become unwieldy to handle with current technology, if all zoom levels should cover the same geographic area.Īs an example, Google Maps cover the whole world in one single 256×256 pixel image at its outermost zoom level. The concept described above, storing multiple images of the geographic area covered, but with different scales, is commonly called zoom levels, since the increasing scale can be envisioned as “zooming” into the map, making features larger and larger while also revealing more detail. For a general purpose map, this can’t be done easily.Īn alternative is to produce several maps at different scales, from large scale overview maps, down to highly detailed maps. This is fine if the purpose of the map is known before hand: the scale and size can be optimized for one purpose. This digital equivalent of a paper map has the same limitations as a paper map: the amount of detail is limited by the size of the image adding more detail without cluttering the map forces us to either increase the size of the image, or reduce the scale of the map. Lets go through how one could go about creating a map to be published on the internet.Īs a first attempt, we scan a paper map and publish the resulting bitmap image on the internet. Today, almost all maps on the internet aimed to the public use tiling. It made maps on the internet popular in 2005, by stitching together 256 by 256 pixel images of the whole world at remarkable detail. Google Maps is most certainly the prime example of a tiled map. That what appears to the user as one large map image, is really put together from a number of smaller images, tiles, that are drawn next to each other, without seams, to create the illusion of a much larger image. IntroductionĪ common way to display maps on computers, especially on the internet, is to use so called tiled maps. A good start before reading this document is for example mapschool. It assumes basic knowledge about maps and geography. It covers the basics as well as a lot of technical detail on how tiling maps work, for example projections and how coordinates are handled.
![mapproxy tms resolutions zoom levels mapproxy tms resolutions zoom levels](https://josm.openstreetmap.de/raw-attachment/wiki/Help/Preferences/Imagery/PreferencesImagerySettings.png)
MAPPROXY TMS RESOLUTIONS ZOOM LEVELS FREE
This is a short, free and open introduction to the concept of tiled maps.