獲取raster對象的某一個波段的顏色表信息，返回顏色表的JSON格式。

語法

text ST_ColorTable(raster raster_obj, integer band);

參數(shù)

參數(shù)名稱 描述
raster_obj raster對象。
band 指定的波段序號，從0開始。

描述

顏色表的JSON格式：

  • 4分量：
    '{"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}
    ]
}'
  • 3分量：
    '{"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}
    ]
}'

如果不存在顏色表，函數(shù)返回空值。

示例

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}
    ]
}'