Imagery services and formats
The same imagery can be delivered as a downloadable raster, cloud object or map service. Choose the form that matches the task.
| Format/service | Best for | Main limitation |
|---|---|---|
| GeoTIFF | local raster analysis | large files |
| Cloud Optimised GeoTIFF (COG) | cloud/HTTP subset access and analysis | needs COG-capable software for full benefit |
| WMS | rendered map images | not the source raster; server controls rendering |
| WMTS | fast tiled basemap | fixed tile scales/styles |
| XYZ | simple web/client tiles | normally display rather than analysis |
| image service | dynamic server-side raster functions where supported | vendor/service capabilities vary |
COG
A COG is a GeoTIFF organised with internal tiling/overviews and byte-range-friendly layout so a client can request only the parts needed. LINZ's public AWS imagery is delivered as COGs.
WMS versus WMTS
WMS renders a requested map extent, which is flexible but can be slower. WMTS serves pre-defined tiles and is ideal for basemaps. LINZ Aerial Basemap uses WMTS/XYZ rather than WMS as its primary tile interface.
Raster analysis
Do not run pixel analysis on a screenshot or JPEG tile if the underlying analytical GeoTIFF/COG exists. Use the source raster and its metadata.
For live vector services see the forthcoming APIs and web services material; for LINZ imagery use LINZ Basemaps.
Last reviewed: 26 August 2026