ST_Band
Name
ST_Band — Returns one or more bands of an existing raster as a new raster. Useful for building new rasters from existing rasters.
Synopsis
raster
ST_Band
(
raster
rast
, integer[]
nbands = ARRAY[1]
)
;
raster
ST_Band
(
raster
rast
, integer
nband
)
;
raster
ST_Band
(
raster
rast
, text
nbands
, character
delimiter=,
)
;
Description
Returns one or more bands of an existing raster as a new raster. Useful for building new rasters from existing rasters or export of only selected bands of a raster or rearranging the order of bands in a raster. If no band is specified or any of specified bands does not exist in the raster, then all bands are returned. Used as a helper function in various functions such as for deleting a band.
For the
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Availability: 2.0.0
Examples
-- Make 2 new rasters: 1 containing band 1 of dummy, second containing band 2 of dummy and then reclassified as a 2BUI SELECT ST_NumBands(rast1) As numb1, ST_BandPixelType(rast1) As pix1, ST_NumBands(rast2) As numb2, ST_BandPixelType(rast2) As pix2 FROM ( SELECT ST_Band(rast) As rast1, ST_Reclass(ST_Band(rast,3), '100-200):1, [200-254:2', '2BUI') As rast2 FROM dummy_rast WHERE rid = 2) As foo; numb1 | pix1 | numb2 | pix2 -------+------+-------+------ 1 | 8BUI | 1 | 2BUI
-- Return bands 2 and 3. Using array cast syntax SELECT ST_NumBands(ST_Band(rast, '{2,3}'::int[])) As num_bands FROM dummy_rast WHERE rid=2; num_bands ---------- 2 -- Return bands 2 and 3. Use array to define bands SELECT ST_NumBands(ST_Band(rast, ARRAY[2,3])) As num_bands FROM dummy_rast WHERE rid=2;
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--Make a new raster with 2nd band of original and 1st band repeated twice, and another with just the third band SELECT rast, ST_Band(rast, ARRAY[2,1,1]) As dupe_band, ST_Band(rast, 3) As sing_band FROM samples.than_chunked WHERE rid=35;