Re: [gdal-dev] NTF/JPEG2000 Question

[Ivan Lucena]

Frank,

I am having a similar problem with a files like that. They are taking more than 3 seconds just to open on gdalinfo or any GDALOpen() call. That wouldn't be a problem except in a case where we are running a large bath process with several gdal_translate runs frequently. 

But as far I can tell the GCP are right on the corner pixels, so it would be very fast to interpret it as a GeoTransform matrix. Would that be safe to change the driver's code to do that?

Regards,

Ivan


>  -------Original Message-------
>  From: Frank Warmerdam <warmerdam at pobox.com>
>  To: Logan Greenlee <lgreenlee at digitalresultsgroup.com>
>  Cc: gdal-dev at lists.osgeo.org <gdal-dev at lists.osgeo.org>
>  Subject: Re: [gdal-dev] NTF/JPEG2000 Question
>  Sent: Jul 17 '11 10:32
>  
>  On Sun, Jul 17, 2011 at 8:16 AM, Logan Greenlee
>  <lgreenlee at digitalresultsgroup.com> wrote:
>  > Sorry - here are the GCP's:
>  ...
>  > Is there any particular reason mapserver can't use the GCP's for display? Is it that they are not necessarily corner points of the image?
>  
>  Logan,
>  
>  It is just not a feature of MapServer to support warping
>  (rubber sheeting) of images on the fly based on GCPs.  It
>  would be fairly computationally expensive to do this so I
>  deemed it not very useful in MapServer.  It also isn't something
>  I've seen requested often.
>  
>  However, MapServer does support reprojecting images on
>  the fly which is similarly computationally expensive, so it
>  might make sense to add a mechanism to MapServer to use
>  gdal transformers (such as polynomial warping using GCPs)
>  as an option. It would require some development.
>  
>  Best regards,
>  --
>  ---------------------------------------+--------------------------------------
>  I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
>  light and sound - activate the windows | http://pobox.com/~warmerdam
>  and watch the world go round - Rush    | Geospatial Software Developer
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