[Gdal-dev] Problem With black Collar with gdal warp

[Frank Warmerdam]

Pietro Buratti wrote:
> Hi,
> I have a "big" problem with Reprojected GeoTIFF Images because They have 
> a black collar after the reprojection and It's impossible to collect 
> them in a singular GeoTIFF.
>  
> Could you help me?
> I must use only gdal utilities ...

Pietro,

One option is to reproject them directly into an existing mosaic file.
Another is to mosaic them after reprojection with knowledge of the black
nodata value (though this runs the risk of black pixels in the image being
treated as nodata).  You could also add an alpha band when reprojecting
to keep track of valid and invalid pixels (gdalwarp's -dstalpha switch).

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