[Gdal-dev] ArcGrid to IMG conversion: huge file

[Thom DeCarlo]

Markus,
The IMG format doesn't support the concept of "NODATA", and by default does
not use compression. It does support ESRI-style run length encoding, but I
haven't seen it used much. You might do better converting to geotiff which
supports LZW compression and Frank has extended it to support a NODATA tag.

--
Thom DeCarlo
------------------------------------------------------
           Experience is a wonderful thing
It allows you to recognize a mistake when you make it again.

> -----Original Message-----
> From: Markus Neteler
> Sent: Thursday, March 09, 2006 6:04 AM
> To: GDAL-dev list
> Subject: [Gdal-dev] ArcGrid to IMG conversion: huge file
> 
> Hi,
> 
> when converting the
>   Landscan Global Population 2000 Database
> from
>   http://www.fao.org/geonetwork/srv/en/metadata.show?id=1261
> 
[snip]
> 
> Apparently the NoData isn't passed to IMG.
> Is the created IMG file probably uncompressed
> which leads to this big file size?
> 
> Best regards
> 
>  Markus
>