ST_Count
Prev 9.9. Raster Band Statistics and Analytics Next

Name

ST_Count — Returns the number of pixels in a given band of a raster or raster coverage. If no band is specified defaults to band 1. If exclude_nodata_value is set to true, will only count pixels that are not equal to the nodata value.

Synopsis

bigint ST_Count(raster rast, integer nband=1, boolean exclude_nodata_value=true);

bigint ST_Count(raster rast, boolean exclude_nodata_value);

bigint ST_Count(text rastertable, text rastercolumn, integer nband=1, boolean exclude_nodata_value=true);

bigint ST_Count(text rastertable, text rastercolumn, boolean exclude_nodata_value);

Description

Returns the number of pixels in a given band of a raster or raster coverage. If no band is specified nband defaults to 1.

[Note]

If exclude_nodata_value is set to true, will only count pixels with value not equal to the nodata value of the raster. Set exclude_nodata_value to false to get count all pixels

Availability: 2.0.0

Examples

--example will count all pixels not 249 and one will count all pixels.  --
SELECT rid, ST_Count(ST_SetBandNoDataValue(rast,249)) As exclude_nodata, 
        ST_Count(ST_SetBandNoDataValue(rast,249),false) As include_nodata
    FROM dummy_rast WHERE rid=2;
				    
rid | exclude_nodata | include_nodata
-----+----------------+----------------
   2 |             23 |             25

See Also

ST_SetBandNoDataValue

Prev Up Next
ST_SetBandIsNoData Home ST_Histogram