Improve upsampling behavior

boku-ilen / geodot-plugin

Godot plugin for loading geospatial data

GNU General Public License v3.0

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Improve upsampling behavior #2

Closed kb173 closed 4 years ago

kb173 commented 4 years ago

Currently, images are always sampled with the nearest-neighbor method. This results in 256x256 images with huge pixels at small scales. In most cases, this is not what we want.

We should introduce a flag with which the upsampling behavior can be set. Possibilities are:

Proper interpolation (e.g. for heightmaps)
No interpolation, generate smaller images at small scales
If easily doable: Color-preserving upsampling (something like EPX scaling - e.g. for land-use data)

kb173 commented 4 years ago

https://github.com/boku-ilen/geodot-plugin/commit/c2bc03a7b6f551e8999bee68e88f4574b182f963 introduced proper scaling for heightmaps (bilinear upsampling, nearest neighbor downsampling). The other interpolation types are still to do.

kb173 commented 4 years ago

All GDAL upsampling behaviors are now available to Geodot via a function argument with https://github.com/boku-ilen/geodot-plugin/commit/03df7529041059171ea2aa3ea875c01f7732ca5d.

Unfortunately, I have found no good method of doing something like EPX scaling. The modal methods seem to go in this direction, but they don't help with upscaling. #5 is responsible for improvements in that regard.