This topic describes the ST_SetValue function. This function changes the pixel value
based on a geometry or the row and column of a raster.
Syntax
raster ST_SetValue(raster raster_obj,
integer row,
integer column,
double value,
integer band);
raster ST_SetValue(raster raster_obj,
geometry geom,
double value,
integer band default 0,
boolean rebuild_pyd default true,
cstring setvalueOptions default '');
Parameters
| Parameter |
Description |
| raster_obj |
The specified raster object. |
| row |
The row number of the pixel value that is changed. |
| column |
The column number of the pixel value that is changed. |
| value |
The new pixel value. |
| band |
The band number of the pixel value that is changed. |
| rebuild_pyd |
Specifies whether to rebuild the pyramid. |
| setvalueOptions |
The change options of a pixel value. The value of this parameter is a JSON string.
For more information, see Table 1.
|
Table 1. Fields in the setvalueOptions parameter
| Field |
Type |
Default value |
Description |
| window_clip |
bool |
false |
Specifies whether to use the bounding box of the geometry object to clip the raster
object.
- true: uses the minimum bounding rectangle (MBR) of the geometry object as the region
for changing the pixel value.
- false: uses the geometry object as the region for changing the pixel value.
|
| rast_coord |
bool |
false |
Specifies whether the input geometry uses pixel coordinates.
- true: Pixel coordinates are used. The x-coordinate specifies the column number of
a pixel and the y-coordinate specifies the row number of a pixel. The valid values
of the x-coordinate and y-coordinate start from 0.
- false: Pixel coordinates are not used.
|
Examples
select st_value(rast, 0, 2, 1) from raster_table order by id;
update raster_table set rast=st_setvalue(rast, ST_geomfromtext('MULTIPOINT(0 0, 2 2, 10 10)', 4326),250.0, 0, true);
update raster_table set rast=st_setvalue(rast, ST_geomfromtext('LINESTRING(211 77, 233 100)', 4326), 10.0, 0, false, '{"rast_coord":true}');