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}
]
}'