[postgis-tickets] [PostGIS] #2912: rt_raster_gdal_polygonize: Couldn't create a OGR Datasource to store pols

[PostGIS]

#2912: rt_raster_gdal_polygonize: Couldn't create a OGR Datasource to store pols
----------------------+-----------------------------------------------------
  Reporter:  strk     |       Owner:  dustymugs
      Type:  defect   |      Status:  closed   
  Priority:  medium   |   Milestone:           
 Component:  raster   |     Version:  trunk    
Resolution:  invalid  |    Keywords:           
----------------------+-----------------------------------------------------

Comment(by strk):

 So I found that these errors were due to setting skew to the requested
 output skew in gdal_warp for so called "default georeferenced" rasters.
 Similarly to what was done for scale by r12928

 Here's the patch:
 {{{
 diff --git a/raster/rt_core/rt_warp.c b/raster/rt_core/rt_warp.c
 index 10964c4..369eaf4 100644
 --- a/raster/rt_core/rt_warp.c
 +++ b/raster/rt_core/rt_warp.c
 @@ -999,6 +999,8 @@ rt_raster rt_raster_gdal_warp(
                  *       I'm not sure the above division was needed */
                 gt[1] = _scale[0] * 10;
                 gt[5] = -1 * _scale[1] * 10;
 +               gt[2] = _skew[0]; /* skew_x */
 +               gt[4] = _skew[1]; /* skew_y */

                 rt_raster_set_geotransform_matrix(rast, gt);
                 rt_raster_set_srid(rast, SRID_UNKNOWN);
 }}}

 Without the patch, calling _st_gdalwarp with a skew results in the wrong
 skew being set to the output raster if the raster has the default
 georeference (like #2911 was for scale). I'm not sure if there's a public
 API to affect skew.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2912#comment:4>
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