[gdal-dev] GTiff optimisation

[Yves Jacolin]

Etienne,

Ah yes I understand :)

Actually I tested geotifcp to add projection information in the geotiff file but 
I had some problem. Since I have ECW files also I moved to gdal utilities.

Merci !

Y.
Le mardi 30 août 2011 15:09:13, Etienne Tourigny a écrit :
> Bonjour Yves,
> 
> 
> I think that gdalwarp is not optimized for saving compressed geotiffs, you
> would have to do that in a second step. This topic has been addressed in
> this list not long ago.
> 
> 
> Anyway, you should be using gdal_translate (with a_srs flag) instead for
> this task, as you are just adding georeferencing information, not
> re-projecting the data.
> 
> something like gdal_translate -co "COMPRESS=PACKBITS" -co
> "PHOTOMETRIC=MINISWHITE" -co "NBITS=1" -a_srs "EPSG:2154" input.tif
> output.tif
> 
> Etienne
> 
> 
> 
> ----- Original Message -----
> From: Yves Jacolin <yjacolin at free.fr>
> To: gdal-dev <gdal-dev at lists.osgeo.org>
> Cc:
> Sent: Tuesday, August 30, 2011 8:22:46 AM
> Subject: [gdal-dev] GTiff optimisation
> 
> Hello,
> 
> I am converting GTiff to GTiff in order to add projection and
> georeferencing information in the header. I am using gdalwarp with some
> flags, mailny -co flags. I have some question about this.
> 
> Here is my command line:
> 
> gdalwarp -co "COMPRESS=PACKBITS" -co "PHOTOMETRIC=MINISWHITE" -co "NBITS=1"
> - s_srs "EPSG:2154" -t_srs "EPSG:2154" input.tif output.tif
> 
> 1.  File size: input.tif and output.tif have different file size, output
> file is 50 % bigger than the input file. Is it normal?
> 
> 2. If I use gdalinfo on my output file, I have no information about
> MINISWHITE parameter while I have it in the input file. Am I using this
> creation option correctly? This issue could be related to the first item?
> 
> 3. I also have a "AREA_OR_POINT=Area" item in my output from gdalinfo, what
> does it means?
> 
> gdal version: GDAL 1.7.3, released 2010/11/10
> 
> thanks,
> 
> Y.

-- 
Yves Jacolin

http://yjacolin.gloobe.org