[Gdal-dev] EHdr: was ESRI flt nbits issue

[Cees Wesseling]

Markus,

The problem is that the EHdr driver is "misused" to read the .flt 
format. That ESRI format is generated from the ESRI GRIDFLOAT command.
That command will not generate the nbits line.
The ESRI white paper does not mentioned float data at all.

At present the GDAL EHdr driver can read the flt format by recognizing 
some additional tags such as xllcorner, etc. in addition to ulxmap etc 
mentioned in the white paper.
However the Create call of the EHdr driver will not create a format 
compatible with the ESRI FLOATGRID command.
A new separate driver should be the best option to support the .flt 
format more robust. That can easily be programmed by cloning some of the 
EHdr code.

But all confusion arises from the fact that some applications generate 
float data as ".bil" format while that is not supported in the white 
paper and some of these applications use "a different from the rest" 
approach to mixing the .flt and .bil format  for their purposes.

Regards, Cees

-- 
Cees Wesseling
PCRaster Environmental Software
van Swindenstraat 97
3514 XP Utrecht
The Netherlands
Tel. 0031-(0)30-238012-4 (-5 Fax)