[postgis-devel] [PostGIS] #925: [raster] ST_Transform

[PostGIS]

#925: [raster] ST_Transform
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 Reporter:  dustymugs       |       Owner:  dustymugs            
     Type:  task            |      Status:  assigned             
 Priority:  medium          |   Milestone:  PostGIS Raster Future
Component:  postgis raster  |     Version:  trunk                
 Keywords:                  |  
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Comment(by dustymugs):

 For PostGIS 2.0, a basic ST_Transform function should be provided.  These
 functions use GDAL's Warp API, specifically the C function
 GDALAutoCreateWarpedVRT().  This function allows us to quickly provide an
 ST_Transform function for rasters at the expense of not doing multiple
 actions at the same time as the reprojection (e.g. changing the pixel
 scale or the skew).  It is expected that the C function
 GDALAutoCreateWarptedVRT() will be replaced with a more generic function
 matching that used in the GDAL utility gdalwarp.

 1. ST_Transform(rast raster, srid integer[, algorithm text DEFAULT
 'NearestNeighbor']) -> raster

   raster: the raster to reproject to a new spatial reference system.  if
 raster's SRID is -1, the function returns NULL

   srid: the id of the spatial reference system to reproject the raster

   algorithm: the resampling algorithm to use.  This argument is case-
 insensitive.  The default algorithm is "NearestNeighbor".  Possible
 algorithms are

 {{{
 NearestNeighbour

 Bilinear

 Cubic

 CubicSpline

 Lanczos
 }}}

 ''The docs for GDAL function GDALAutoCreateWarpedVRT() does not indicate
 if the Lanczos algorithm is supported but is provided above in the list of
 possible algorithms for the eventual replacement of the
 GDALAutoCreateWarpedVRT() function with a more generic GDAL warp
 function''

 {{{
 ST_Transform(raster, 3310)

 ST_Transform(raster, 4326, 'Cubic')

 ST_Transform(raster, 3309, 'Bilinear')
 }}}

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/925#comment:7>
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