On mercredi 13 juin 2018 22:14:07 CEST Markus Metz wrote: > Many raster bands contain nodata, therefore it would be helpful if the > number of non-nodata grid cells could be reported by gdalinfo in some way. > > The number of non-nodata grid cells is not available through > GDALGetRasterStatistics() / GDALRasterBand::GetStatistics(), probably > because approximations can be stored as raster band statistics, and the > number of non-nodata grid cells is unknown in case of approximations. > > Therefore I suggest to report the number of non-nodata grid cells only if > all grid cells are evaluated, i.e. with > > *gdalinfo -mm* Force computation of the actual min/max values for each band > in the dataset. > > The number of non-nodata grid cells would be a small piece of quite useful > information to quickly evaluate the usefulness of a raster band. > > Asking for the possibility to enhance a bit the output of gdalinfo,
Markus, That would be more something triggered by -stats since this number of non- nondata cells is an intermediate result of GDALRasterBand::ComputeStatistics() in gcore/gdalrasterband.cpp. To make it sensical even in the case of approximate statistics, why not computing a percentage instead ? That would need to be saved in a metadata item, let's say STATISTICS_VALID_RATIO (between 0 and 1) ? Wanna take a crack at implementing this ?Otherwise file an enhancement ticket about that. By the way, since GDAL 2.3.0, there's a STATISTICS_APPROXIMATE=YES metadata item so as to know if the stats have been computed in an approx way or not Even -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev
