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Image of Australia as a map, its extent, and map projection.

Usage

ga_topo

Format

A list with an array, a numeric vector, and a character vector:

img

image array with dimension 921,1025,3 - three slices Red, Green, Blue

extent

the geographic extent of the array, in metres

crs

the map projection of the geographic extent of img

Details

This dataset exists to demonstrate the full pattern: write img to PNG, texture it with [quad_texture()] using extent, and transform the mesh vertices with the crs - the image itself is never resampled.

(The image is web Mercator, aka 'EPSG:3857'. We've kept the proj string because it's the easiest way to modify a projection.)

Provenance

Copyright Commonwealth of Australia (Geoscience Australia) 2016. Creative Commons Attribution 4.0 International Licence.

The image is named 'Australian Topographic Base Map (Web Mercator)' and is from the following Geoscience Australia Web Map Tile Service (WMTS): https://services.ga.gov.au/gis/rest/services/Topographic_Base_Map/MapServer.

Code to obtain the image is in 'data-raw/ga_topo.R' at https://github.com/hypertidy/textures using the wmts package https://github.com/mdsumner/wmts.