By default, QGIS does not seem to recognize "Value Tables" (VAT) the way ArcGIS does. So far I cannot find a way to represent the pixel values discretely, or apply a "legend" to the layer. Is there something that can be done to associate the VAT with the raster in QGIS? Ultimately I'd like to symbolize and see the joined values when I use the "Identify" tool on a pixel?
For example, I've downloaded a landcover GeoTIFF from the NRCS that contains a single "Pixel Value" field, which represents the type of landcover. In addition to the GeoTIFF, the authors included a "Value table" (
<filename>.vat.dbf), which essentially is "joined" to the raster to give a plain English description of the "Pixel Value", as well as RGB values. There are 17 discrete values in the VAT, but a small sample looks like this:
Value Count Red Green Blue Land_Cover 0 299079 0.00000000000 0.00000000000 0.00000000000 Unclassified 11 3896533 0.27843137255 0.41960784314 0.62745098039 Open Water 12 86735 0.81960784314 0.86666666667 0.97647058824 Perennial Snow/Ice 21 4527275 0.86666666667 0.78823529412 0.78823529412 Developed, Open Space
This data can be downloaded from the "National Land Cover Dataset by State" at https://datagateway.nrcs.usda.gov/GDGHome_DirectDownLoad.aspx