ST_SetColorTable-PolarDB(PolarDB)-阿里云帮助中心

Sets the color table of a specified band in a raster object. The color table is provided in JSON format.

Syntax

raster ST_SetColorTable(raster rast, integer band_sn, cstring clb);

Parameters

Parameter	Description
`rast`	The raster object.
`band_sn`	The sequence number of the band. Band numbering starts from 0.
`clb`	The color table in JSON format. For the JSON structure, see ST_ColorTable.

Examples

The following example sets a four-component color table on band 0 of a raster object.

UPDATE rast SET rast = ST_SetColorTable(rast, 0,
'{"compsCount": 4,
    "entries": [
        {"value": 0, "c1": 0, "c2": 0, "c3": 0,   "c4": 255},
        {"value": 1, "c1": 0, "c2": 0, "c3": 85,  "c4": 255},
        {"value": 2, "c1": 0, "c2": 0, "c3": 170, "c4": 255}
    ]
}');

Output:

(1 row)