Duh What tool should I use to show relevant tiff-info, and I'll post that info on the gdal-dev list instead.
On Apr 21, 2012, at 8:25 AM, Frank Warmerdam wrote: > On 12-04-21 07:32 AM, Heikki Julkunen wrote: >> First, thanks all for a great set of tools! >> >> Anyway, I've seen this mentioned in a post elsewhere, but there was no reply. >> I'm not sure who to 'blame', gdal or imagemagick, but it seems like the >> alpha channel >> embedded by imagemagick is NOT compatible with gdal. The transparency is NOT >> used. >> (since imagemagick has no clue about geo-data after image processing I use >> geotifcp to add that). >> >> Example: gdalinfo bad-example.tif >> <<geo meta removed>> >> Band 1 Block=10020x1 Type=Byte, ColorInterp=Red >> Band 2 Block=10020x1 Type=Byte, ColorInterp=Green >> Band 3 Block=10020x1 Type=Byte, ColorInterp=Blue >> Band 4 Block=10020x1 Type=Byte, ColorInterp=Undefined >> >> A working file looks like this: >> gdalinfo good-example.tif >> <<geo meta removed>> >> Band 1 Block=10020x1 Type=Byte, ColorInterp=Red >> Mask Flags: PER_DATASET ALPHA >> Band 2 Block=10020x1 Type=Byte, ColorInterp=Green >> Mask Flags: PER_DATASET ALPHA >> Band 3 Block=10020x1 Type=Byte, ColorInterp=Blue >> Mask Flags: PER_DATASET ALPHA >> Band 4 Block=10020x1 Type=Byte, ColorInterp=Alpha >> >> I.e, it seems like the alpha from imagemagick is global but gdal expects a >> per dataset alpha ? > > Heikki, > > This would likely be better pursued on the gdal-dev mailing list, but it > is not possible to evaluate without seeing the tiffinfo report for the > file in question. It may be an "associated" vs. "unassociated" alpha > problem. > > Best regards, > -- > ---------------------------------------+-------------------------------------- > I set the clouds in motion - turn up | Frank Warmerdam, [email protected] > light and sound - activate the windows | http://home.gdal.org/warmerda > and watch the world go round - Rush | Geospatial Software Developer > > _______________________________________________ > UbuntuGIS mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/ubuntu > http://trac.osgeo.org/ubuntugis/wiki _______________________________________________ UbuntuGIS mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/ubuntu http://trac.osgeo.org/ubuntugis/wiki
