[QGIS-Developer] WMST raster resampling is NOT resampling?

[Richard Duivenvoorde]

In QGIS when you load a raster, in the style properties there is an 
option 'Resampling'.
Which then gives the user different options, for zoomed in and zoomed 
out.
I'm not sure if the Oversampling option is used for both or only for 
out...

The corresponding docs are not very clear:
https://docs.qgis.org/testing/en/docs/user_manual/working_with_raster/raster_properties.html#resampling

Sometimes users report thatafter loading a WMTS they want to soften the 
image a little, and use these options to do so.
While this works well for aerial photo's, the provider then fetcheds the 
4 tiles from the ascending zoom level, and uses those.
BUT for non aerial photo's (like topo maps), this fails, as the map view 
actually changes (because of the change of the zoomlevel, also the 
labels and scale dependent layers etc etc change)..

If you want to test:

A public aerial:
https://geodata.nationaalgeoregister.nl/luchtfoto/rgb/wmts?request=GetCapabilities&service=WMTS
layer: 2016_ortho25

A public topo:
https://geodata.nationaalgeoregister.nl/wmts?VERSION=1.0.0&request=GetCapabilities
layer: opentopo

Is this deliberately? Is the resampling of an actual tile image not 
doable?

Anybody has some input/insight in this?

Regards,

Richard Duivenvoorde