spherical mercator

This category contains 3 posts

On-the-fly reprojection of tiles using your favorite conventional WMS servers

If we accept Spherical Mercator tiles and the ZXY storage scheme as standard and still wish to use all the nice WMS servers we know, we can easily set up a middle tile server like this: For example, this request gets a OSM-like tile from a conventional Bavarian WMS server:,TK50&x=8711&y=5643&z=14 The advantage of this … Continue reading

Madrid 1656

The year 1656 saw the creation in Madrid of -at least- two graphic masterpieces: while Velázquez was doing that, the Portuguese cartographer Pedro Teixeira was doing this (click to enlarge): A superb map of Madrid in the times of the late Spanish Habsburgs. You can download it as a georeferenced (EPSG:25830) ECW file and also … Continue reading

Tile pyramids versus TIFF, ECW and such on mobile devices

Due to poor performance and portability issues associated with raster libraries, I don’t think it’s a good idea to use raster formats such as TIFF, ECW or MrSID on mobile devices such as (smart)phones, pocket PCs, tablets, etc. Google Maps, OpenLayers and OpenStreetMap have made quadtree tiles very popular. Initially intended to increase web mapping … Continue reading