[postgis-tickets] [PostGIS] #4215: Drop usage of GDALPolygonize in DT_DumpAsPolygons

[PostGIS]

#4215: Drop usage of GDALPolygonize in DT_DumpAsPolygons
--------------------+---------------------------
 Reporter:  komzpa  |      Owner:  Bborie Park
     Type:  defect  |     Status:  new
 Priority:  medium  |  Milestone:  PostGIS 2.4.6
Component:  raster  |    Version:  2.4.x
 Keywords:          |
--------------------+---------------------------
 http://brian-mcgill-4.ums.maine.edu/postgis_zonal.pdf :

 {{{
 However this function is
 inadequate for the current purpose – it merges pixels with the same value
 into larger polygons. In
 principle this should still be acceptable but the actual implementation
 (in a poorly documented
 “feature”) does this by converting every value to an integer. So pixels
 with a temperature of
 13.49 and 12.51 are merged incorrectly (and the value stored is 13 which
 is also incorrect) }}}

 Looking at code we have branching on whether GDAL>F<Polygonize is
 available, and that looks hardcoded to "no". We're supporting GDAL 1.10+
 and GDALFpolygonize is available since 1.9.0, so branching can be removed.

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4215>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.