[Qgis-developer] QgsRasterLayer::drawMultiBandColor

Marco Hugentobler marco.hugentobler at karto.baug.ethz.ch
Sun Aug 19 03:00:31 EDT 2007

I found that the georeferencer sets 0 as nodata value itself. So I changed the 
georeferencer behaviour and I will commit the second (more robust) version of 
the if-statement to svn.


On Friday 17 August 2007 08:33:33 Marco Hugentobler wrote:
> On Thursday 16 August 2007 21:35:50 Peter Ersts wrote:
> > requires only one value in the channel stack to be nodata to skip the
> > current pixel and would be the most robust case
> >
> > In your situation where you want 0,0,0 to be 'nodata', but 0,255,255 to
> > display that would best be done by setting 0,0,0 as transparent pixel
> > rather than saying 0 is the nodatavalue.
> I agree that the second version is more robust.
> My image example is created by the QGIS georeferencer. Maybe I could change
> something there that it uses NaN as nodata value instead of 0. Currently,
> it uses the same nodata value as the input image for georeferencing.
> Regards,
> Marco

Dr. Marco Hugentobler
Institute of Cartography
ETH Zurich
Technical Advisor QGIS Project Steering Committee
marco.hugentobler at karto.baug.ethz.ch

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