[gdal-dev] Envi driver and complex dataset

[Frank Warmerdam]

Julien Michel wrote:
> Dear Gdal developpers,
> 
> Yesterday I was trying to read my favourite radar dataset, consisting in
> a raw file along with an ENVI style header with gdal 1.6.2. I was very 
> confident since it was working perfectly fine with earlier version of gdal.
> 
> But this time, I only managed to get this error message from gdalinfo:
> 
> ERROR 1: The file does not have a value for the data type
> that is recognised by the GDAL ENVI driver.
> 
> So I took a glimpse at my header file, which is using 6 as a data type,
> the right data type code for my complex dataset.
> 
> I took a walk into gdal source code in order to try to spot the error
> and I came up with these lines (frmts/raw/envidataset.cpp:1791):
> 
> /*  Removed JBP, ITT-VIS 11/29/2007.  Complex data does not display
> properly in the ArcGIS application so we are removing it from the
> supported types list. This is a bit of a big hammer as it may remove
> functionality from some direct GDAL users, but this data is extremely
> problematic from an ArcGIS standpoint.   */
> /*          case 6:
>             eType = GDT_CFloat32;
>             break;
> 
>             case 9:
>             eType = GDT_CFloat64;
>             break;
> */
> 
> So this is it. No wonder why I can not use my dataset anymore. I must 
> say that I'm very surprised that every gdal users looses a valuable (SAR 
> users will agree for sure) supported dataset types just to accomodate 
> one software which is not able to display complex data.
> 
> Is it possible to do something to get these types back to working properly?

Julien,

I have also seen this note and was someone surprised.

Please file a ticket and we can look at having it re-enabled in trunk.
ArcGIS 9.4 will not be affected and hopefully after that work can be done
within ArcGIS to treat such data adequately or this can be made specific
to ArcGIS builds.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent