PostGIS
Name
ST_Reskew — Resample a raster by adjusting only its skew (or rotation parameters). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. Default is NearestNeighbor.
Synopsis
raster +`*`+ST_Reskew*(`raster `rast, double precision
skewxy, text algorithm=NearestNeighbor, double precision
maxerr=0.125`)`;
raster +`*`+ST_Reskew*(`raster `rast, double precision
skewx, double precision skewy, text
algorithm=NearestNeighbor, double precision maxerr=0.125`)`;
Description
Resample a raster by adjusting only its skew (or rotation parameters). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. The default is NearestNeighbor which is the fastest but results in the worst interpolation.
skewx and skewy define the new skew.
The extent of the new raster will encompass the extent of the provided raster.
A maxerror percent of 0.125 if no maxerr is specified.
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Availability: 2.0.0 Requires GDAL 1.6.1+
Changed: 2.1.0 Works on rasters with no SRID
Examples
A simple example reskewing a raster from a skew of 0.0 to a skew of 0.0015.
-- the original raster non-rotated
SELECT ST_Rotation(ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0));
-- result
0
-- the reskewed raster raster rotation
SELECT ST_Rotation(ST_Reskew(ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0), 0.0015));
-- result
-0.982793723247329