[Gdal-dev] Re: Gdal_translate issues

[Frank Warmerdam]

Sampson, David wrote:
> Do you have any fresh ideas of how I can go about my gdal_translate 
> block. To knock my three step process (as posted to the list) to a one 
> step process.

Dave,

I've gone through some of your emails, but I got a bit mixed up about what
is the current issue.  First a few clarifications on points that seemed
to be raised.

  1) If you use -outsize to reduce the size of the image at the same time
     as you are attaching gcps, you will also need to adjust the pixel/line
     locations of the gcps to be in terms of the reduced image size, not
     the original.  I think this is the core of your problem.

  2) On review, gdal_translate never adjusts the GCP pixel/line locations,
     though I think it should.  So this should be considered a bug in
     gdal_translate and I'd encourage you to file a bug on the issue,
     especially if it is affecting your ability to function.

  3) You asked if Vincent's bug about GCP projections could be affecting
     you (http://bugzilla.remotesensing.org/show_bug.cgi?id=1354).  I'm
     not sure - it is possible.  So as to feel like I've accomplished something
     I dug into this issue tonight and fixed it in CVS.

Could you summarize what is still going wrong, with an exact report of
the commands you are using, the gdalinfo reports before and after
transformation and what you think isn't as you would expect it to be?

Best regards,

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