ST_BandPixelType — Returns the type of pixel for given band. If no bandnum specified, 1 is assumed.
text ST_BandPixelType(raster rast, integer bandnum=1);
Returns name describing data type and size of values stored in each cell of given band.
There are 11 pixel types. Pixel Types supported are as follows:
1BB - 1-bit boolean
2BUI - 2-bit unsigned integer
4BUI - 4-bit unsigned integer
8BSI - 8-bit signed integer
8BUI - 8-bit unsigned integer
16BSI - 16-bit signed integer
16BUI - 16-bit unsigned integer
32BSI - 32-bit signed integer
32BUI - 32-bit unsigned integer
32BF - 32-bit float
64BF - 64-bit float
SELECT ST_BandPixelType(rast,1) As btype1,
ST_BandPixelType(rast,2) As btype2, ST_BandPixelType(rast,3) As btype3
FROM dummy_rast
WHERE rid = 2;
btype1 | btype2 | btype3
--------+--------+--------
8BUI | 8BUI | 8BUI