[gdal-dev] Geotiff nodata handling

2014-06-18 Thread Andrea Aime
Hi, I'm trying to wrap my head around how gdal handles nodata values. In an image with this gdalinfo exceprt: Band 1 Block=512x512 Type=Byte, ColorInterp=Red NoData Value=0 Band 2 Block=512x512 Type=Byte, ColorInterp=Green NoData Value=0 Band 3 Block=512x512 Type=Byte, ColorInterp=Blue NoDat

Re: [gdal-dev] Geotiff nodata handling

2014-06-18 Thread Even Rouault
Le mercredi 18 juin 2014 18:35:49, Andrea Aime a écrit : > Hi, > I'm trying to wrap my head around how gdal handles nodata values. > In an image with this gdalinfo exceprt: > > Band 1 Block=512x512 Type=Byte, ColorInterp=Red > NoData Value=0 > Band 2 Block=512x512 Type=Byte, ColorInterp=Green >

Re: [gdal-dev] Geotiff nodata handling

2014-06-23 Thread Jukka Rahkonen
Even Rouault mines-paris.org> writes: > This is a rather tricky area indeed. > > A few facts : > - The concept of nodata value in GDAL is something per band, which leave > multi-band processing of nodata values subject to interpretation. > - The TIFFTAG_GDAL_NODATA extension tag in TIFF only ho