This function is used to convert a specified pixel of a raster into a geometric object that is represented by the point in the center of the geometric object.

Syntax

geometry ST_PixelAsPoint(raster raster_obj,
    integer row default 0,
    integer column default 0,
    integer pyramid default 0) ;

Parameters

Parameter Description
raster_obj The raster that you want to query.
row The number of the row in which the pixel resides. Valid row numbers start from 0, which indicates the pixel in the upper-left corner of the raster.
column The number of the column in which the pixel resides. Valid column numbers start from 0, which indicates the pixel in the upper-left corner of the raster.
pyramid The pyramid level in which the pixel resides.

Description

This function converts a specified pixel of a raster into a geometric object that is represented by the point in the center of the geometric object. You can obtain the same result for a pixel if you set the ref_point parameter of the ST_PixelAsPoint function to CENTER.

Examples

SELECT ST_AsText(ST_PixelAsCentroid(rast, 10, 10))
FROM rast_table
WHERE id = 10;

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POINT(-178.2 88.2)