Creating a Deepzoom map for Dioramas
The goal is to create a “Deep Zoom” map of my dioramas.
unlike streetview the deep Zoom format is very easy to create because it is based on the tiled web map “standard”
path: assets/images/Tiled_web_map.png alt: “exploped tile web map example”
Properties of tiled web maps that require convention or standards include the size of tiles, the numbering of zoom levels, the projection to use, the way individual tiles are numbered or otherwise identified, and the method for requesting them. Most tiled web maps follow certain Google Maps conventions:
Tiles are 256x256 pixels
At the outer most zoom level, 0, the entire world can be rendered in a single map tile.
Each zoom level doubles in both dimensions, so a single tile is replaced by 4 tiles when zooming in. This means that about 22 zoom levels are sufficient for most practical purposes.
path: assets/images/TilePyramid.jpg alt: “tile Pyramid example”
The Web Mercator projection is used, with latitude limits of around 85 degrees.
The de facto OpenStreetMap standard, known as Slippy Map Tilenames or XYZ, follows these and adds more:
An X and Y numbering scheme
PNG images for tiles
Images are served through a Web server, with a URL like http://…/Z/X/Y.png, where Z is the zoom level, and X and Y identify the tile.
Tile numbering schemes
There are three main numbering schemes in use:
Google Maps / OpenStreetMap: (0 to 2zoom-1, 0 to 2zoom-1) for the range (-180, +85.0511) - (+180, -85.0511)
Tile Map Service: (0 to 2zoom-1, 2zoom-1 to 0) for the range (-180, +85.0511) - (+180, -85.0511). (That is, the same as the previous with the Y value flipped.) QuadTrees, used by Microsoft.
path: assets/images/overhead-crane.png alt: “overhead crane / Gantry crane image sourced from www.indiamart.com/”
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