Ticket #4035 (closed defect: fixed)
Can't open binary grids created with ArcGIS 10
|Reported by:||cdestigter||Owned by:||warmerdam|
Description (last modified by cdestigter) (diff)
We're having problems with a binary grid created in ArcGIS 10. The equivalent grid created in 9.3 works fine.
With reference to the AIG format notes, it seems a few things are different than gdal expects:
- magic number is 00 00 27 0A FF FF FC 08, (not one of the two known magic numbers listed)
- tile type for many tiles (seems to be the ones with NODATA as the top left pixel) is 0x80 (not one of the known tile types in gdal/frmts/aigrid )
- RMinSize is 0x0 for each tile (seems odd? maybe okay)
The statistics are also a bit weird for the arcgis 10 grid (they're all zero):
Min=1.000 Max=6.000 Minimum=0.000, Maximum=0.000, Mean=0.000, StdDev=0.000 NoData Value=255 Overviews: 1459x1000, 730x500, 365x250 Metadata: STATISTICS_MINIMUM=0 STATISTICS_MAXIMUM=0 STATISTICS_MEAN=0 STATISTICS_STDDEV=0
Not sure why there are a Min/Max? but also different min/max statistics in the metadata.
With client permission, I've uploaded the two grids for testing purposes, as well as a small python script that reproduces the problem. They're here: http://dl.dropbox.com/u/2649727/gdal-aig-test.zip
The test script shows that after converting to GTiff, the ArcGIS 10 grid has nothing but zeroes in it, but the 9.3 grid has the correct data (values 1-6).
Tested on gdal 1.7.3