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

[Markus Neteler]

Cees,

On Mon, Jan 23, 2006 at 11:13:19AM +0100, Cees Wesseling wrote:
> 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.

thanks for telling me - I was about to complain to my
data provider!

> 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.

Thanks for the update!

 Markus