Le mercredi 12 juin 2013 19:58:20, Graeme B. Bell a écrit : > Also: > > (using -init 255 will produce a TIFF with suitable nodata values in the > second scenario I described, as a workaround. > > However, gdal_rasterize still does not produce correct command line output > in this situation, and also it should not be necessary for users to > manually add a -init option and manually synchronise the value with the > -a_nodata value to ensure valid output from gdal_rasterize)
The fact that the first example inits the output TIFF to the nodata value is specific to the working of the GeoTIFF driver, that returns non-instanciated blocks initialized to the nodata value. With other output drivers, you could also get a raster initialized to 0 instead of the nodata value. If you really want to initialize the raster with a particular value in a reliable way, always use -init. I've pushed a fix in the dev version so that the progress bar appears in the second case (SQL with 0 resulting rows). > > On Jun 12, 2013, at 7:50 PM, Graeme Bell <[email protected]> wrote: > > Summary: > > > > I noticed that gdal_rasterize invents data values instead of burning > > nodata values, incorrectly, in what is probably a common situation - a > > valid query returning geometry columns but zero polygon rows. > > > > Command line output suggests that nothing is being done, yet a GeoTIFF > > with data values is silently rendered in the background. > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Geospatial professional services http://even.rouault.free.fr/services.html _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
