photoshop geotiff

[joerg p]

Frank Warmerdam wrote:
> joerg p wrote:
>
>> hello,
>>
>> I would like to adjust colors of a geotiff in photoshop:
>>
>> Before editing I can display it with mapserver and open it with
>> globalmapper
>> then I open the file in photoshop
>> i adjust the color
>> i save the tiff
>> I write the geotiff tag again with GeoTiffExamine
>>
>> But now i can't display it with mapserver and when I open it with
>> globalmapper, it says:
>> 'wrong data type 1 for XML Packet'; tag ignored
>> 'unknown field with tag 34665 encountered'
>>
>> How do I save it right with photoshop?
>> I have no compression and tried also tif for mac and pc, no difference.
>
>
> Joerg,
>
> If there aren't too many special non-geotiff tags you want to preserve,
> you might just want to run the file through gdal_translate.  This should
> drop out unusual Photoshop tags, though in general "wrong data type ...
> tag ignored" messages should not be fatal in processing.
>
> However, I would be interested in getting a smallish sample of the file
> if possible.  Was the XML Package tag in question put in by Photoshop or
> GeoTiffExamine?
>
> Best regards,

hello Frank,

thanks for your help, that was the problem. And now I can also display
UTM geotiffs, which never worked before.

One more question (and a lot more in the next post :-)
The datum of the file is completely dropped (WGS84). How do I set it? I
tried:
gdal_translate.exe -a_srs "+datum=WGS84" daten/test.tif
daten/test_transl2.tif
but of course it doesn't work.

I think the XML Package tag in question was put in by Photoshop.
How can I give you a sample? The original file has around 220MB...

Maybe you have also some suggestions for my next post
'basic questions for my project'

Thanks
Joerg