[gdal-dev] NITF Chip

[Even Rouault]

Le lundi 10 juin 2013 18:13:47, Baker, Anthony W a écrit :
> I have a NITF file which I can read fine with GDAL.  The issue that it is a
> chip and using the transformation to determine geolocations fails (for
> example finding the chip's four corners).  Instead of placing a point
> based on the chip, it places it based on the whole image.  I can read the
> metadata and see that the RPC metadata contains the chip offset: RPC
> Metadata:
>   LINE_OFF=3276
>   LINE_SCALE=3276
>   SAMP_OFF=2538
>   SAMP_SCALE=2538
>   LONG_OFF=-106.8927
>   LONG_SCALE=0.0542
>   LAT_OFF=32.3084
>   LAT_SCALE=0.0593
>   HEIGHT_OFF=1229
>   HEIGHT_SCALE=1214
> 
> I am tempted to use the LINE_OFF and SAMP_OFF to make the adjustments to
> properly get the boundary.  I believe this is only a partial solution (not
> generic enough) and will just give further problems as I get other NITF
> chips.  Would someone help me with the proper way of handling the chip
> transformation?

Anthony,

I'm not sure from your above text how you tried to make use of the RPC 
metadata. Did you try "gdalwarp -rpc the.nitf out.tif" ?

Best regards,

Even

> 
> Thank you,
> 
> Anthony

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