GDALOpen failed on GRC grid — at Initial Version
|Reported by:||mladen||Owned by:||warmerdam|
|Severity:||major||Keywords:||gdalopen, grc, vertical mapper, northwood, gdal_translate|
There is an error when trying to open a GRC grid (Northwood VerticalMapper Classified Grid) with gdal_translate. The command and error is: C:\>gdal_translate -of vrt "C:\temp\ClassficationGrid-UK-Technologies_1.grc" "C:\temp\ClassficationGrid-UK-Technologies_1.vrt"
ERROR 4: `C:\temp\ClassficationGrid-UK-Technologies_1.grc' not recognised as a supported file format.
GDALOpen failed - 4 This seems like it could be a problem with the file, but I can open it in MapInfo, as well as Global Mapper 13, so I think the file is OK. I put the .grc/.tab file pair in a zip (~5.3 Mb) at http://dl.dropbox.com/u/53500018/GdalOpenFailedGrid.zip if it helps.
I did some more research, and compared a working grid against the one that fails to open. Here is the working grid, which is almost exactly the same as the failing one (~50K difference in file sizes): http://dl.dropbox.com/u/53500018/WorkingGdalOpen.zip Comparing the two in a binary editor, I see differences in bytes 10 and 26 of the header... not sure exactly what that means without the GRC spec. However, as noted above, the failing grid does open correctly in other software (MapInfo and Global Mapper 13), so I suspect that there may be a bug in the GDAL GRC driver.