ST_Tile
Indietro  11.3. Raster Constructors  Avanti

Nome

ST_Tile — Restituisce un insieme di raster risultanti dalla suddivisione del raster di input in base alle dimensioni desiderate dei raster di output.

Sinossi

setof raster ST_Tile(raster rast, int[] nband, integer width, integer height, boolean padwithnodata=FALSE, double precision nodataval=NULL);

setof raster ST_Tile(raster rast, integer nband, integer width, integer height, boolean padwithnodata=FALSE, double precision nodataval=NULL);

setof raster ST_Tile(raster rast, integer width, integer height, boolean padwithnodata=FALSE, double precision nodataval=NULL);

Description

Restituisce un insieme di raster risultanti dalla suddivisione del raster di input in base alle dimensioni desiderate dei raster di output.

Se padwithnodata = FALSE, le tessere dei bordi sui lati destro e inferiore del raster possono avere dimensioni diverse dal resto delle tessere. Se padwithnodata = TRUE, tutte le tessere avranno le stesse dimensioni, con la possibilità che le tessere dei bordi vengano imbottite con valori NODATA. Se le bande del raster non hanno valori NODATA specificati, è possibile specificarne uno impostando nodataval.

[Nota]

Se una banda specificata del raster di input è fuori-db, anche la banda corrispondente nei raster di output sarà fuori-db.

Disponibilità: 2.1.0

Esempi

Code
WITH foo AS (
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 2, '8BUI', 10, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, 0, 1, -1, 0, 0, 0), 1, '8BUI', 2, 0), 2, '8BUI', 20, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, 0, 1, -1, 0, 0, 0), 1, '8BUI', 3, 0), 2, '8BUI', 30, 0) AS rast UNION ALL

    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -3, 1, -1, 0, 0, 0), 1, '8BUI', 4, 0), 2, '8BUI', 40, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -3, 1, -1, 0, 0, 0), 1, '8BUI', 5, 0), 2, '8BUI', 50, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -3, 1, -1, 0, 0, 0), 1, '8BUI', 6, 0), 2, '8BUI', 60, 0) AS rast UNION ALL

    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -6, 1, -1, 0, 0, 0), 1, '8BUI', 7, 0), 2, '8BUI', 70, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -6, 1, -1, 0, 0, 0), 1, '8BUI', 8, 0), 2, '8BUI', 80, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -6, 1, -1, 0, 0, 0), 1, '8BUI', 9, 0), 2, '8BUI', 90, 0) AS rast
), bar AS (
    SELECT ST_Union(rast) AS rast FROM foo
), baz AS (
    SELECT
        row_number() OVER (
            ORDER BY ST_UpperLeftY(rast) DESC, ST_UpperLeftX(rast)
        ) AS tile_id,
        rast
    FROM (
        SELECT ST_Tile(rast, 3, 3, TRUE) AS rast
        FROM bar
    ) AS tiled
)
SELECT
    tile_id,
    ST_UpperLeftX(rast) AS ulx,
    ST_UpperLeftY(rast) AS uly,
    ST_Value(rast, 1, 1, 1) AS band1,
    ST_Value(rast, 2, 1, 1) AS band2
FROM baz;
Output
tile_id | ulx | uly | band1 | band2
---------+-----+-----+-------+-------
       1 |   0 |   0 |     1 |    10
       2 |   3 |   0 |     2 |    20
       3 |   6 |   0 |     3 |    30
       4 |   0 |  -3 |     4 |    40
       5 |   3 |  -3 |     5 |    50
       6 |   6 |  -3 |     6 |    60
       7 |   0 |  -6 |     7 |    70
       8 |   3 |  -6 |     8 |    80
       9 |   6 |  -6 |     9 |    90
(9 rows)
Code
WITH foo AS (
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 2, '8BUI', 10, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, 0, 1, -1, 0, 0, 0), 1, '8BUI', 2, 0), 2, '8BUI', 20, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, 0, 1, -1, 0, 0, 0), 1, '8BUI', 3, 0), 2, '8BUI', 30, 0) AS rast UNION ALL

    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -3, 1, -1, 0, 0, 0), 1, '8BUI', 4, 0), 2, '8BUI', 40, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -3, 1, -1, 0, 0, 0), 1, '8BUI', 5, 0), 2, '8BUI', 50, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -3, 1, -1, 0, 0, 0), 1, '8BUI', 6, 0), 2, '8BUI', 60, 0) AS rast UNION ALL

    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -6, 1, -1, 0, 0, 0), 1, '8BUI', 7, 0), 2, '8BUI', 70, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -6, 1, -1, 0, 0, 0), 1, '8BUI', 8, 0), 2, '8BUI', 80, 0) AS rast UNION ALL
    SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -6, 1, -1, 0, 0, 0), 1, '8BUI', 9, 0), 2, '8BUI', 90, 0) AS rast
), bar AS (
    SELECT ST_Union(rast) AS rast FROM foo
), baz AS (
    SELECT
        row_number() OVER (
            ORDER BY ST_UpperLeftY(rast) DESC, ST_UpperLeftX(rast)
        ) AS tile_id,
        rast
    FROM (
        SELECT ST_Tile(rast, ARRAY[2], 3, 3) AS rast
        FROM bar
    ) AS tiled
)
SELECT
    tile_id,
    ST_UpperLeftX(rast) AS ulx,
    ST_UpperLeftY(rast) AS uly,
    ST_Value(rast, 1, 1, 1) AS band_value
FROM baz;
Output
tile_id | ulx | uly | band_value
---------+-----+-----+------------
       1 |   0 |   0 |         10
       2 |   3 |   0 |         20
       3 |   6 |   0 |         30
       4 |   0 |  -3 |         40
       5 |   3 |  -3 |         50
       6 |   6 |  -3 |         60
       7 |   0 |  -6 |         70
       8 |   3 |  -6 |         80
       9 |   6 |  -6 |         90
(9 rows)

Si veda anche

ST_Union, ST_Retile