Re: Support for Terrain-RGB
Even Rouault via gdal-dev <[email protected]>
| Newsgroups | gmane.comp.gis.gdal.devel |
|---|---|
| Message-ID | <[email protected]> |
Related ticket (regarding Terrarium) in https://github.com/OSGeo/gdal/issues/14520 . I'm not sure what the solution is, but that proliferation of RGB formats to encode elevations doesn't look pretty.... Le 05/01/2026 à 15:15, Lars Ahlzen via gdal-dev a écrit : > Hi all, > > For Open/WebGL-based client side map rendering libraries, like > MapLibre or Mapbox GL, Terrain-RGB [1] (original spec by MapBox I > believe) seems to be the elevation encoding of choice. > > The encoding itself, meant for use with 8-bits per channel RGB raster > formats such as PNG tiles, is straightforward: > > elevation (in meters) = -10000 + 0.1 * (R * 65536 + G * 256 + B) > > As far as I know a separate tool is typically used for the encoding, > such as rio-rgbify [2] from Mapbox. There's an example writeup of such > workflow at [3]. Perhaps the same thing could also be achieved using > the raster calculator (gdal_calc), but that seems far from trivial for > most users. > > It looks like it would be relatively easy to add native support for > this in GDAL, perhaps as another mode in gdaldem. Would it make sense > if I gave that a try? > > - Lars > > [1] https://blog.mapbox.com/global-elevation-data-6689f1d0ba65 > [2] https://github.com/mapbox/rio-rgbify > [3] https://github.com/syncpoint/terrain-rgb/blob/master/README.md > > _______________________________________________ > gdal-dev mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/gdal-dev -- http://www.spatialys.com My software is free, but my time generally not. _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev