[Gdal-dev] ENVISAT data comes out left-right fliped

[Julien Demaria]

Joaquim,

This isn't a bug.
MERIS Envisat files are geolocated using a GCPs list (in fact one GCP 
every 16 pixels). In the swath the file is left-right fliped, but it's 
the specifications. If you want apply the GCPs projection and then flip 
LR the file, you should use the gdalwarp GDAL utility:
gdalwarp MER_RR__1_Mediterranean.n1 MER_RR__1_Mediterranean.tif
(tested on Linux with FWTools-linux-1.0.0a7).

I've successfully viewed your file using FWTools OpenEV (FWTools1.0.0a8 
on Windows). With it you can directly display (unflipped) your .n1 file 
since OpenEV reproject on-the-fly the file using GCPs :)


Regards,

Julien


jluis a écrit :
> 
>> Can you provide a pointer to a dataset that demonstrates
>> this, and details on how you came to the conclusion?   This
>> should all be submitted in bugzilla.
> 
> 
> Frank,
> I got this file from a tutorial of Bilko
> (http://www.noc.soton.ac.uk/bilko/)
> Biko opens it correctly but my code that reads gdal
> recognized formats into matlab shows it "fliplr"
> The same happens when we use gdal_translate
> 
> gdal_translate.exe -b 5 MER_RR__1_Mediterranean.n1 lixo.tif
> 
> Its not obvious that the image is flipped because it's
> a bit dark, but you can see that Italy is flipped.
> 
> ftp.ualg.pt/users/jluis/MER_RR__1_Mediterranean.zip
> 
> Joaquim
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