ST_ColorTable - AnalyticDB

擷取raster對象的某一個波段的顏色表資訊，返回顏色表的JSON格式。

文法

text ST_ColorTable(raster raster_obj, integer band);

參數

參數名稱	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，函數返回空值。

樣本

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}
    ]
}'