This topic describes the ST_Envelope function, which obtains the bounding box of a raster.

Syntax

geometry ST_Envelope(raster source);
geometry ST_Envelope(raster source,
                     integer pyramid);

Parameters

Parameter Description
source The raster whose bounding box you want to obtain.
pyramid The pyramid level at which the raster resides. Valid values start from 0. Default value: 0.

Description

This function obtains the bounding box of a raster.

Bounding box

Example

SELECT st_astext(st_envelope(rast_object))
FROM raster_table;

----------------------------------------------------
 POLYGON((-180 90,180 90,180 -90,-180 -90,-180 90))

--Specify the pyramid level at which the raster resides.                 
SELECT st_astext(st_envelope(rast_object,  1))
FROM raster_table;

----------------------------------------------------
 POLYGON((-180 90,180 90,180 -90,-180 -90,-180 90))