On Wed, 18 Dec 2019 at 04:37, Even Rouault <[email protected]> wrote: > > Hi, > > Following a number of exchanges on the PROJ mailing list, related to PROJ 6 > integration in QGIS, I've prepared a pull request changing a bit how we deal > with the 'early-binding' TOWGS84 term in > https://github.com/OSGeo/gdal/pull/2113 > > The aim is to avoid the propagation of potentially suboptimal TOWGS84 terms by > default (except when exporting to PROJ4 string as we don't have a more > expressive way of encoding datum information), which can be the source of > later problems (not using grids when available due to this towgs84 being > strictly honoured). > > I've a backport of this for the 3.0 branch ready, to go in the 3.0.3 release.
Even -- I think this is totally the right move (from my (partial!) understanding of the problem), as it means that downstream clients like QGIS will be able to grab a lossless representation of the original dataset's CRS via WKT. I'd be happy to follow this logic in QGIS too, i.e. if coming from a WKT definition then a bound CRS != its source CRS, but if coming from a proj string then a bound crs == its source crs. That'd give much desired consistency across the different tools. Thanks for working through this! Nyall > > Even > > -- > Spatialys - Geospatial professional services > http://www.spatialys.com > _______________________________________________ > gdal-dev mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
