[GRASS-user] GRASS export GeoTiff adventure :-)

[Markus Metz]

All I wanted to say is that for best allround compatibility, the GEOTiff 
output should be kept as simple as possible. If a raster export is meant 
to be used in a particular known application, the native raster file 
format of this application if existing might be preferable.
The gdal defaults INTERLEAVE=PIXEL and TILED=NO work fine, but can 
surely be fine tuned. Only PROFILE might need adjustment to GeoTIFF or 
BASELINE, says gdal documentation.
This thread seems to be about ESRI compatibility, so ESRI .hdr labelled 
Raster should definitively work.

Maciej Sieczka wrote:
>
>>> 8. There are several compression methods? Does compression affect 
>>> significantly reading/displaying an image?
> From my limited experience with ESRI products, LZW dose not pose
> problems and provides an optimal tradeoff between the render times and
> file size. Deflate seems less supported and although compresses better
> requires more CPU power to decompress.
LZW is pretty good for a raster with many different cell values (e.g. 
imagery, elevation, NDVI) whereas packbits is great for a raster with 
only few categories (e.g. land cover classification).
Again, for ESRI there is also ESRI .hdr labelled, otherwise for best 
allround compatibility I would recommend not to use compression.
ESRI file format support is listed here:
http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Technical_specifications_for_raster_dataset_formats
>
>> TFW=YES would only be needed if you export a raster for an
>> application that can not read GeoTIFF internal metadata.
>
> Yet it never hurts to create a TFW just in case ;).
Actually I remember once some ESRI application (can't remember which one 
and what version) really wanted a TFW file for GEOTiff, so it sure 
doesn't hurt and can help.

Markus