Name
ST_MakeEmptyCoverage — 使用空栅格平铺网格覆盖地理参考区域。
Synopsis
raster
ST_MakeEmptyCoverage
(
integer
tilewidth
, integer
tileheight
, integer
width
, integer
height
, double precision
upperleftx
, double precision
upperlefty
, double precision
scalex
, double precision
scaley
, double precision
skewx
, double precision
skewy
, integer
srid=unknown
)
;
描述
Create a set of raster tiles with
ST_MakeEmptyRaster
. Grid dimension is
width
&
height
. Tile dimension is
tilewidth
&
tileheight
. The covered georeferenced area is from upper left corner (
upperleftx
,
upperlefty
) to lower right corner (
upperleftx
+
width
*
scalex
,
upperlefty
+
height
*
scaley
).
![[Note]](images/note.png)
|
|
|
请注意，scaleY对于栅格通常为负，scalex通常为正。因此，与左上角相比，右下角的y值更低，x值更高。 |
可用性：2.4.0
示例基本知识
在4x4网格中创建16个瓷砖，以覆盖从左上角(22，77)到右下角(55，33)的WGS84区域。
SELECT (ST_MetaData(tile)).* FROM ST_MakeEmptyCoverage(1, 1, 4, 4, 22, 33, (55 - 22)/(4)::float, (33 - 77)/(4)::float, 0., 0., 4326) tile;
upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands
-------------------------------------------------------------------------------------
22 | 33 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
30.25 | 33 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
38.5 | 33 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
46.75 | 33 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
22 | 22 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
30.25 | 22 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
38.5 | 22 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
46.75 | 22 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
22 | 11 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
30.25 | 11 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
38.5 | 11 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
46.75 | 11 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
22 | 0 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
30.25 | 0 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
38.5 | 0 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0
46.75 | 0 | 1 | 1 | 8.25 | -11 | 0 | 0 | 4326 | 0