Overriding GeoTIFF projection with world file

Rahkonen Jukka Jukka.Rahkonen at MMMTIKE.FI
Wed Feb 6 17:04:40 EST 2008

Frank Warmerdam wrote:
> Rahkonen Jukka wrote:
>>> 3) well, I'm sure there are other methods.
>> How about trying to motivate some clever developer to create the option I
>> mentioned... Point 1) might give me possibilities for making an investment.
>> I fear this feature is not too much of general interest.


> From a coding point of view this is not complicated.  The function
> msGetGDALGeoTransform() is used for all code needing a gdal geotransform and
> it is trivial to make the GDALGetGeoTransform() call lower priority than
> the world file or ows metadata.  I'm just not sure I could justify this
> as a change to make to the core mapserver software.

> If you wanted to keep this as a local change in your own builds of mapserver
> you can change that function around somewhat.  Of course, this might
> introduce a configuration management issues on your end in the long term.

> I don't really need any financial motivation in this case.  It's more of a
> concern that we may be introducing too many quirky behaviors in the software.
> If you *really* need it I could add an undocumented PROCESSING option that
> can be set on a layer and that msGetGDALGeoTransform() would use to decide
> on priority of checks.


I have been considerering the situation and yes, I think I would *really* 
like to use this trick if it exists.  In general, wouldn't it make at least
some sense to first check something that is fast and simple to edit or 
rename or delete if needed (world file in this case), and not something 
like GeoTIFF tags which are much more hard and expensive to handle?


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