[Geotiff] Re: Hep on GeoTiff

[Frank Warmerdam]

Ricardo Fonseca wrote:
> //Geotiff geokeys declaration
> 
> geocode_t projFalseEasting,   projFalseNorthing;
> 
> //Geokeys (example of how I'm calling)
> 
> GTIFKeyGet(gtif, ProjFalseEastingGeoKey, &projFalseEasting, 0, 1); 
> GTIFKeyGet(gtif, ProjFalseNorthingGeoKey, &projFalseNorthing, 0, 1);
> 
> //Closing
> 
> GTIFFree(gtif);
> 
> XTIFFClose(tif);
> 
> ----xxx----
>  
>  
> This is a small example of how I'm using the library. Can you please 
> help me?
> Another thing I want to retrieve and don't know how is the xResolution 
> and yResolution of the pixel, as well as its type (byte, integer, short, 
> long or double). Can you help me also in this subject?

Ricardo,

In the above scenario the projFalseEasting and projFalseNorthing variables
should be double's, not geocode_t (whatever that is).

Otherwise your approach seems fine.  Note that many files will not have
all the geotags, so you need to be careful to check whether you got a
value or not from GTIFKeyGet().  I believe GTIFKeyGet() returns zero if it
did not find the tag, and nonzero if it does get a value.

Best regards,

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