Graeme B. Bell <grb <at> skogoglandskap.no> writes:
> It would be great if the people behind gdal_polygonise could put some thought into this extremely common > situation for anyone working with country or continent scale rasters to make sure that it is handled well. > It has certainly affected us a great deal when working with data at up to 2m resolution for a country larger > than the UK... This really feels like the old "how to eat an elephant problem" and you have answered already by implementing your 'rbuild' system. It seems to be an enhanced version of the traditional solution "one bite at a time" because it can make many parallel bites at a time. I would call it something like "The Piranha Polygonizer (TM)". By the Jungle Software, Inc. It sounds good, doesn't? Analogous problem is making point in polygon queries from huge polygons and this document by Alessandro Furieri has a nice coloured picture about it http://www.gaia-gis.it/spatialite-3.0.0-BETA1/WorldBorders.pdf. So the question is who is the first to make a piranha version of gdal_polygonize.py which takes tile size and perhaps number of thread as input parameters. The default output could be one polygon file for each raster tile because for many use cases it would be just perfect. Combining vector tiles later and making unions of adjacent polygons with same attribute values feels trivial and fast. But this is a non-programmers opinion only. -Jukka Rahkonen- _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
