On vendredi 4 octobre 2019 12:44:18 CEST mhw-at-yg wrote: > > I don't see VRT cascading of any help here, from what I've understood of > > your > > > use case. I think you have no other choice than replicating <Category> and > > <ColorTable> in all <VRTRasterBand> > > Ok. Thanks for confirming my understanding. > > Next question: It appears that <Category> <ColorTable> are order-of-index > based. Meaning that: if "Evergreen" is first element in the category list it > is matched to the first element in the color list. So there is no way in > vrt to specify a lookup table of style "name == pixel_value" like the > below? > > Pixel_Value Category > ------------- ------------------ > 1 Evergreen Forest > 2 Deciduous Forest > ... > 14 Barren > 15 Water > > > I've worked around this by inserting an "n/a" category and 0,0,0 colour > table as first line in each. Without that in qgis and arcmap everything is > shifted by one and 'Deciduous' is assigned to pixel value 1 and 'Water' to > 14. >
You could also potentially use a raster attribute table. See GDALRasterAttributeTable in https://gdal.org/drivers/raster/vrt.html The documentation is a bit loose. The values for Type and Usage match the enumerations at https://github.com/OSGeo/gdal/blob/master/gdal/gcore/gdal.h#L1189 -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev