I have been trying to open Esri grid format (*.adf) files in QGIS. I can display the raster set itself, however, the appropriate attribute data fails to join the spatial dataset.
Can QGIS display the full source raster for ArcGIS?
Or is it a 'proprietary' format that can only be fully displayed in ArcGIS?
Qgis uses gdal to access .adf rasters, Arcinfo Binary Grids (note: .adf files are also used for Arcinfo vectors). Reading the reverse engineered Arc/Info Binary Grid Format description page one sees
vat.adf: This relates to the value attribute table. This is the table corresponding integer raster values with a set of attributes. I presume it is really just a pointer into info in a manner similar to the pat.adf file in a vector coverage, but I haven't investigated yet.
So, no Qgis probably can't read Arcinfo raster attributes. That document was written a long time ago though, so perhaps things have changed.
I don't have access to a vat-enabled raster right now so can't test, but I surmise the structure outlined in the Raster dataset attribute tables Arcgis help is likely quite similar to the vat.adf structure, for those wishing to plug the hole in the format description and perhaps extend the gdal aigrid format driver.
For those of you coming to this question in 2022 there is now a QGIS plugin funded by NOAA called Raster Attribute Table Plugin that allows you to load the attribute table and stylize your layer by the classes defined in the table.
