ST_UpperLeftY — Returns the upper left Y coordinate of raster in projected spatial ref.
float8 ST_UpperLeftY(raster rast);
Returns the upper left Y coordinate of raster in projected spatial ref.
SELECT rid, ST_UpperLeftY(rast) As uly
FROM dummy_rast;
rid | uly
-----+---------
1 | 0.5
2 | 5793244