ST_MakeEmptyCoverage — Cover georeferenced area with a grid of empty raster tiles.
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)
;
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 that scaley is generally negative for rasters and scalex is generally positive. So lower right corner will have a lower y value and higher x value than the upper left corner. |
Availability: 2.4.0
Create 16 tiles in a 4x4 grid to cover the WGS84 area from upper left corner (22, 77) to lower right corner (55, 33).
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