This function returns the color table of a band of a raster object in JSON format.

Syntax

text ST_ColorTable(raster raster_obj, integer band);

Parameters

Parameter Description
raster_obj The raster object.
band The band sequence number, starting from 0.

Description

The following code shows color tables in JSON format.

  • Four color components:
    '{"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}
        ]
    }'
  • Three color components:
    '{"compsCount":3,
        "entries":[
            {"value":0,"c1":0,"c2":0,"c3":0},
            {"value":1,"c1":0,"c2":0,"c3":85},
            {"value":2,"c1":0,"c2":0,"c3":170}
        ]
    }'

If the band does not have a color table, the function returns null.

Examples

select ST_ColorTable(raster_obj,0) from raster_table where id = 1;

__________________________________
'{"compsCount":3,
    "entries":
    [
        {"value":0,"c1":0,"c2":0,"c3":0},
        {"value":1,"c1":0,"c2":0,"c3":85},
        {"value":2,"c1":0,"c2":0,"c3":170}
    ]
}'