[Gdal-dev] Gdal_translate and the Internal accuracy of ground control points

[Frank Warmerdam]

Rahkonen Jukka wrote:
> Hi,
> 
> I have inserted ground control points into a GeoTIFF image file with
> gdal_translate in this way: gdal_translate input.tif  output_gcp.tif -gcp 0
> 0  285113.632 6713217.584 etc.
> 
> Gdalinfo reports me about the resulting image as follows: GCP Projection =
> 
> GCP[  0]: Id=1, Info=
> 
> (0,0) -> (285114,6.71322e+006,0)
> 
> 
> 
> Are the gcp's still stored into the GeoTIFF file with the same accuracy I
> gave them, or are they rounded like gdalinfo is expressing them?

Jukka,

The GCPs are handled and stored as double precision values, so I believe
the original values would be properly preserved.  It is just the gdalinfo
report-to-screen logic which is not displaying the full precision.

Best regards,
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