名称
ST_PixelAsPolygons — 返回包围栅格带的每个像素的多边形几何图形以及每个像素的值、X 和 Y 栅格坐标。
大纲
setof record ST_PixelAsPolygons(raster rast, integer band=1, boolean exclude_nodata_value=TRUE);
Description
返回包围栅格带的每个像素的多边形几何图形以及每个像素的值（双精度）、X 和 Y 栅格坐标（整数）。
返回记录格式：geom geometry，val双精度，x整数，y整数。
![[注意]](../images/note.png)
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When |
可用性: 2.0.0
增强：2.1.0 添加了 except_nodata_value 可选参数。
更改：2.1.1 更改了 except_nodata_value 的行为。
示例
This example returns a raster pixel polygon.
Code
WITH raster AS (
SELECT ST_SetValue(
ST_SetValue(
ST_AddBand(
ST_MakeEmptyRaster(
2, 2, 0, 0, 0.001, -0.001, 0.001, 0.001, 4269
),
1, '8BUI', 1, 0
),
2, 2, 10
),
1, 1, NULL
) AS rast
), pixels AS (
SELECT (ST_PixelAsPolygons(rast)).*
FROM raster
)
SELECT x, y, val, geom AS geom
FROM pixels
ORDER BY x, y;
栅格输出
x | y | val | geom ---+---+----------------------------------------------------------------------------- 1 | 2 | 1 | POLYGON((0.001 -0.001,0.002 0,0.003 -0.001,0.002 -0.002,0.001 -0.001)) 2 | 1 | 1 | POLYGON((0.001 0.001,0.002 0.002,0.003 0.001,0.002 0,0.001 0.001)) 2 | 2 | 10 | POLYGON((0.002 0,0.003 0.001,0.004 0,0.003 -0.001,0.002 0))
Figure