Image of Australia as a map, its extent, and map projection.
ga_topoA list with an array, a numeric vector, and a character vector:
image array with dimension 921,1025,3 - three slices Red, Green, Blue
the geographic extent of the array, in metres
the map projection of the geographic extent of img
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.
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.)