[Gdal-dev] projection in TAB files

[Frank Warmerdam]

Dmitry Kan wrote:
> 
> Hello list!
> 
> I have the task to extract projection information from a TAB file of a 
> raster image (in ECW format) with no data in header and put it to the 
> header of the initial dataset.

Dmitry,

There is no way to update coordinate system or geotransform information
inside an existing ECW file using GDAL.  You would basically have to
re-write the file with the correct information.

 > Is there any way to restore projection from TAB? And will I have an
 > opportunity to introduce a *custom* projection into header of an image
 > in ECW format at all?

I'm not sure what you mean by a custom projection.  In ECW format you
can only write a short PROJECTION name and DATUM name to define a
coordinate system.  These are references to coordinate system definition
files distributed with ERMapper.  There are ways of extending these
dictionary files, and if you did this, you could use your new custom
projections --- but only by setting the PROJ and DATUM creation options
to the ECW driver.

I hope this helps.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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