PostGIS
Name
ST_PixelAsPolygons — Returns the polygon geometry that bounds every pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel.
Synopsis
setof record +`*`+ST_PixelAsPolygons*(`raster `rast, integer
band=1, boolean exclude_nodata_value=TRUE`)`;
Description
Returns the polygon geometry that bounds every pixel of a raster band along with the value (double precision), the X and the Y raster coordinates (integers) of each pixel.
Return record format: `geom geometry, val
double precision, x integer, y` integers.
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Availability: 2.0.0
Enhanced: 2.1.0 exclude_nodata_value optional argument was added.
Changed: 2.1.1 Changed behavior of exclude_nodata_value.
Examples
-- get raster pixel polygon
SELECT (gv).x, (gv).y, (gv).val, ST_AsText((gv).geom) geom
FROM (SELECT ST_PixelAsPolygons(
ST_SetValue(ST_SetValue(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 0.001, -0.001, 0.001, 0.001, 4269),
'8BUI'::text, 1, 0),
2, 2, 10),
1, 1, NULL)
) gv
) foo;
x | y | val | geom
---+---+-----------------------------------------------------------------------------
1 | 1 | | POLYGON((0 0,0.001 0.001,0.002 0,0.001 -0.001,0 0))
1 | 2 | 1 | POLYGON((0.001 -0.001,0.002 0,0.003 -0.001,0.002 -0.002,0.001 -0.001))
2 | 1 | 1 | POLYGON((0.001 0.001,0.002 0.002,0.003 0.001,0.002 0,0.001 0.001))
2 | 2 | 10 | POLYGON((0.002 0,0.003 0.001,0.004 0,0.003 -0.001,0.002 0))See Also
ST_DumpAsPolygons, ST_PixelAsPolygon, ST_PixelAsPoint, ST_PixelAsPoints, ST_PixelAsCentroid, ST_PixelAsCentroids, ST_AsText
ST_PixelAsPolygon |
ST_PixelAsPoint |