This function calculates the pixel coordinates of a cell by using an inverse affine transformation formula based on the world coordinates and pyramid level of the cell.
Syntax
point ST_World2RastCoord(raster raster_obj, integer pyramidLevel, point coord);
geometry ST_World2RastCoord(raster raster_obj, integer pyramidLevel, geometry geom);
Parameters
Parameter | Description |
---|---|
raster_obj | The raster object. |
pyramidLevel | The pyramid level. |
coord | The world coordinates of the cell. |
geom | The geometry to be converted. |
Description
The raster object must have a valid spatial reference system identifier (SRID).
A geometry will be returned. The x coordinate is the column number in raster and the y coordinate is the row number.
Examples
select st_world2rastcoord(rast, 0, '(117.3378,26.9020)'::point) from tb_dem where id = 2;
st_world2rastcoord
--------------------
(53205,32518)
SELECT ST_AsText(ST_world2RastCoord(rast, 0, ST_Rast2WorldCoord(rast, 0, 'POINT(511 0)'::geometry)))
FROM tb_world2rast;
st_astext
--------------
POINT(511 0)