PostGIS
Name
ST_SetBandNoDataValue — Sets the value for the given band that represents no data. Band 1 is assumed if no band is specified. To mark a band as having no nodata value, set the nodata value = NULL.
Synopsis
raster +`*`+ST_SetBandNoDataValue*(`raster `rast, double
precision nodatavalue`)`;
raster +`*`+ST_SetBandNoDataValue*(`raster `rast, integer
band, double precision nodatavalue, boolean
forcechecking=false`)`;
Description
Sets the value that represents no data for the band. Band 1 is assumed if not specified. This will affect results from ST_Polygon, ST_DumpAsPolygons, and the ST_PixelAs…() functions.
Examples
-- change just first band no data value
UPDATE dummy_rast
SET rast = ST_SetBandNoDataValue(rast,1, 254)
WHERE rid = 2;
-- change no data band value of bands 1,2,3
UPDATE dummy_rast
SET rast =
ST_SetBandNoDataValue(
ST_SetBandNoDataValue(
ST_SetBandNoDataValue(
rast,1, 254)
,2,99),
3,108)
WHERE rid = 2;
-- wipe out the nodata value this will ensure all pixels are considered for all processing functions
UPDATE dummy_rast
SET rast = ST_SetBandNoDataValue(rast,1, NULL)
WHERE rid = 2;