Hello Frank, thanks for your reply. Can you let me know how to create a tiffinfo report? What tool do I need to do so? Thanks und best regards Andreas
-----Ursprüngliche Nachricht----- Von: Frank Warmerdam [mailto:warmer...@pobox.com] Gesendet: Freitag, 11. Juni 2010 18:32 An: Fischer, Andreas Cc: gdal-dev@lists.osgeo.org Betreff: Re: [gdal-dev] gdalwarp and GTiff creation option NBITS Fischer, Andreas wrote: > Dear list, > > I try to convert a raster images (GTiff) with gdalwarp. The images only > have two colors (black/white) and the color table just have two entries. > Therefore the file size for each image is exactly as big as needed > (1bit/pixel). The result of gdalwarps transformation are images with > 8bits / pixel and 256 entries in the color table. The file size for each > image is increased but in this case this is without benefit, because > the results are still black and white. > > So I tried the creation option “-co NBITS=1”. Color Table und file size > are now exactly as I expected, but I can’t display the result properly > with any program. For example IrfanView does fine, but unfortunately > MapInfo Professional doesn’t. MapInfo Professional just shows irregular > stripes. After opening the result file in IrfanView and saving it as a > copy, the copy is displayed in MapInfo fine as well. I do not understand > this behavior, because gdalinfo doesn’t show any differences. Andreas, It would be helpful if you could provide a tiffinfo report for each of the three files. It should reveal more of the low level tiff format details which will be needed. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent Diese E-Mail wurde beim Ausgang auf Viren geprueft. Wegen der potentiellen Gefahr auf den Uebertragungswegen wird zu einer Vireneingangskontrolle geraten. Eine Haftung für Virenfreiheit wird ausgeschlossen. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
