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<p>Hi everyone,<br> </p>
<p>I am willing to write down geotiff files.</p>
<p>For instance, i'd like to encode the projection info <code>EPSG:25831</code>.</p>
<p>In order to write down the projection in the geotiff, I am using <code>GTIFSetFromProj4(gtif, proj4String)</code>.</p>
<p>In order to use this method, I first convert <code>EPSG:25831</code> to it's proj4 equivalent via the method <code>proj_as_proj_string</code> (proj library)</p>
<p>This convert <code>EPSG:25831</code> to <code>+proj=utm +zone=32 +datum=WGS84 +units=m +no_defs +type=crs</code></p>
<p>The encoded information are the following;:</p>
<pre><code>Geotiff_Information:
Version: 1
Key_Revision: 1.0
Tagged_Information:
ModelTiepointTag (2,3):
0 0 0
571239.5625 4845679 0
ModelPixelScaleTag (1,3):
2 2 0
End_Of_Tags.
Keyed_Information:
GTModelTypeGeoKey (Short,1): ModelTypeProjected
GeographicTypeGeoKey (Short,1): User-Defined
GeogGeodeticDatumGeoKey (Short,1): User-Defined
GeogEllipsoidGeoKey (Short,1): Ellipse_GRS_1980
ProjectedCSTypeGeoKey (Short,1): User-Defined
ProjectionGeoKey (Short,1): User-Defined
ProjCoordTransGeoKey (Short,1): CT_TransverseMercator
ProjLinearUnitsGeoKey (Short,1): Linear_Meter
ProjNatOriginLongGeoKey (Double,1): 3
ProjNatOriginLatGeoKey (Double,1): 0
ProjFalseEastingGeoKey (Double,1): 500000
ProjFalseNorthingGeoKey (Double,1): 0
ProjScaleAtNatOriginGeoKey (Double,1): 0.9996
End_Of_Keys.
End_Of_Geotiff.
</code></pre>
<p>Unfortunately, in QGIS (my version is QGIS 3.6), the detected CRS is a "generated CRS" and not "EPSG:25831".</p>
<p>What I am doing wrong? Most of the time, our user will choose the projection from the EPSG database, so I always have the EPSG code available if needed.</p>
<p>I am using proj7 and libgeotiff 6.0.</p>
<p>Thank you very much</p>
<p>Kilian<br> </p>
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